[Code of Federal Regulations]
[Title 49, Volume 5]
[Revised as of October 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR571.116]
[Page 334-356]
TITLE 49--TRANSPORTATION
OF TRANSPORTATION
PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS--Table of Contents
Subpart B--Federal Motor Vehicle Safety Standards
Sec. 571.116 Standard No. 116; Motor vehicle brake fluids.
S1. Scope. This standard specifies requirements for fluids for use
in hydraulic brake systems of motor vehicles, containers for these
fluids, and labeling of the containers.
S2. Purpose. The purpose of this standard is to reduce failures in
the hydraulic braking systems of motor vehicles which may occur because
of the manufacture or use of improper or contaminated fluid.
S3. Application. This standard applies to all fluid for use in
hydraulic brake systems of motor vehicles. In addition, S5.3 applies to
passenger cars, multipurpose passenger vehicles, trucks, buses,
trailers, and motorcycles.
S4. Definitions.
Blister means a cavity or sac on the surface of a brake cup.
Brake fluid means a liquid designed for use in a motor vehicle
hydraulic brake system in which it will contact elastomeric components
made of styrene and butadiene rubber (SBR), ethylene and propylene
rubber (EPR), polychloroprene (CR) brake hose inner tube stock or
natural rubber (NR).
Chipping means a condition in which small pieces are missing from
the outer surface of a brake cup.
Duplicate samples means two samples of brake fluid taken from a
single packaged lot and tested simultaneously.
Hydraulic system mineral oil means a mineral-oil-based fluid
designed for use in motor vehicle hydraulic brake systems in which the
fluid is not in contact with components made of SBR, EPR or NR.
Packager means any person who fills containers with brake fluid that
are subsequently distributed for retail sale.
Packaged lot is that quantity of brake fluid shipped by the
manufacturer to the packager in a single container, or that quantity of
brake fluid manufactured by a single plant run of 24 hours or less,
through the same processing equipment and with no change in ingredients.
Scuffing means a visible erosion of a portion of the outer surface
of a brake cup.
A silicone base brake fluid (SBBF) is a brake fluid which consists
of not less than 70 percent by weight of a diorgano polysiloxane.
Sloughing means degradation of a brake cup as evidenced by the
presence of carbon black loosely held on the brake cup surface, such
that a visible black streak is produced when the cup, with a
50010 gram deadweight on it, is drawn base down over a sheet
of white bond paper placed on a firm flat surface.
Stickiness means a condition on the surface of a brake cup such that
fibers will be pulled from a wad of U.S.P. absorbent cotton when it is
drawn across the surface.
S5. Requirements. This section specifies performance requirements
for DOT 3, DOT 4 and DOT 5 brake fluids; requirements for brake fluid
certification; and requirements for container sealing, labeling and
color coding for brake fluids and hydraulic system mineral oils. Where a
range of tolerances is specified, the brake fluid shall meet the
requirements at all points within the range.
S5.1 Brake fluid. When tested in accordance with S6, brake fluids
shall meet the following requirements:
S5.1.1 Equilibrium reflux boiling point (ERBP). When brake fluid is
tested according to S6.1, the ERBP shall not be less than the following
value for the grade indicated:
(a) DOT 3: 205 deg.C. (401 deg.F.).
(b) DOT 4: 230 deg.C. (446 deg.F.).
(c) DOT 5: 260 deg.C. (500 deg.F.).
S5.1.2 Wet ERBP. When brake fluid is tested according to S6.2, the
wet ERBP shall not be less than the following value for the grade
indicated:
(a) DOT 3: 140 deg.C. (284 deg.F.).
(b) DOT 4: 155 deg.C. (311 deg.F.).
(c) DOT 5: 1 180 deg.C. (356 deg.F.).
S5.1.3. Kinematic viscosities. When brake fluid is tested according
to S6.3, the kinematic viscosities in square millimeters per second at
stated temperatures shall be neither less than 1.5 mm\2\/s at 100
deg.C. (212 deg.F.) nor more than the following maximum value for the
grade indicated:
(a) DOT 3: 1,500 mm\2\/s at minus 40 deg.C. (minus 40 deg.F.).
(b) DOT 4: 1,800 mm\2\/s at minus 40 deg.C. (minus 40 deg.F.).
[[Page 335]]
(c) DOT 5: 900 mm\2\/s at minus 40 deg.C. (minus 40 deg.F.).
S5.1.4 pH value. When brake fluid, except DOT 5 SBBF, is tested
according to S6.4, the pH value shall not be less than 7.0 nor more than
11.5.
S5.1.5 Brake fluid stability.
S5.1.5.1 High-temperature stability. When brake fluid is tested
according to S6.5.3 the ERBP shall not change by more than 3 deg.C.
(5.4 deg.F.) plus 0.05 deg. for each degree that the ERBP of the fluid
exceeds 225 deg.C. (437 deg.F.).
S5.1.5.2 Chemical stability. When brake fluid, except DOT 5 SBBF,
is tested according to S6.5.4, the change in temperature of the
refluxing fluid mixture shall not exceed 3.0 deg.C (5.4 deg.F.) plus
0.05 deg. for each degree that the ERBP of the fluid exceeds 225 deg.C
(437 deg.F.).
S5.1.6 Corrosion. When brake fluid is tested according to S6.6--
(a) The metal test strips shall not show weight changes exceeding
the limits stated in Table I.
Table I
------------------------------------------------------------------------
Maximum
permissible
weight
Test strip material change, mg./
sq. cm. of
surface
------------------------------------------------------------------------
Steel, tinned iron, cast iron.............................. 0.2
Aluminum................................................... .1
Brass, copper.............................................. .4
------------------------------------------------------------------------
(b) Excluding the area of contact (131 mm. (\1/
2\\1/32\ inch) measured from the bolt hole end of the test
strip), the metal test strips shall not show pitting or etching to an
extent discernible without magnification;
(c) The water-wet brake fluid at the end of the test shall show no
jelling at 235 deg.C (73.49 deg.F.);
(d) No crystalline deposit shall form and adhere to either the glass
jar walls or the surface of the metal strips;
(e) At the end of the test, sedimentation of the water-wet brake
fluid shall not exceed 0.10 percent by volume;
(f) The pH value of water-wet brake fluid, except DOT 5 SBBF, at the
end of the test shall not be less than 7.0 nor more than 11.5;
(g) The cups at the end of the test shall show no disintegration, as
evidenced by blisters or sloughing;
(h) The hardness of the cup shall not decrease by more than 15
International Rubber Hardness Degrees (IRHD); and
(i) The base diameter of the cups shall not increase by more than
1.4 mm. (0.055 inch).
S5.1.7 Fluidity and appearance at low temperature. When brake fluid
is tested according to S6.7, at the storage temperature and for the
storage times given in Table II--
(a) The fluid shall show no sludging, sedimentation,
crystallization, or stratification;
(b) Upon inversion of the sample bottle, the time required for the
air bubble to travel to the top of the fluid shall not exceed the bubble
flow times shown in Table II; and
(c) On warming to room temperature, the fluid shall resume the
appearance and fluidity that it had before chilling.
Table II--Fluidity and Appearance at Low Temperatures
------------------------------------------------------------------------
Maximum
Storage bubble
Storage temperature time flow time
(hours) (seconds)
------------------------------------------------------------------------
Minus 402 deg.C. (minus 403.6 deg.F.)............................. i4.0
Minus 502 deg.C. (minus 583.6 deg.F.)............................. u0.2
------------------------------------------------------------------------
S5.1.8 Evaporation. When brake fluid is tested according to S6.8--
(a) The loss by evaporation shall not exceed 80 percent by weight;
(b) The residue from the brake fluid after evaporation shall contain
no precipitate that remains gritty or abrasive when rubbed with the
fingertip; and
(c) The residue shall have a pour point below minus 5 deg.C. (+23
deg.F.).
S5.1.9 Water tolerance. (a) At low temperature. When brake fluid is
tested according to S6.9.3(a)--
(1) The fluid shall show no sludging, sedimentation,
crystallization, or stratification;
(2) Upon inversion of the centrifuge tube, the air bubble shall
travel to the top of the fluid in not more than 10 seconds;
(3) If cloudiness has developed, the wet fluid shall regain its
original clarity and fluidity when warmed to room temperature; and
(b) At 60 \C. (140 \F.). When brake fluid is tested according to
S6.9.3(b)--
[[Page 336]]
(1) The fluid shall show no stratification; and
(2) Sedimentation shall not exceed 0.15 percent by volume after
centrifuging.
S5.1.10 Compatibility.
(a) At low temperature. When brake fluid is tested according to
S6.10.3(a), the test specimen shall show no sludging, sedimentation, or
crystallization. In addition, fluids, except DOT 5 SBBF, shall show no
stratification.
(b) At 60 deg.C. (140 deg.F.). When brake fluid is tested
according to S6.10.3(b)--
(1) Sedimentation shall not exceed 0.05 percent by volume after
centrifuging; and
(2) Fluids, except DOT 5 SBBF, shall show no stratification.
S5.1.11 Resistance to oxidation. When brake fluid is tested
according to S6.11--
(a) The metal test strips outside the areas in contact with the
tinfoil shall not show pitting or etching to an extent discernible
without magnification;
(b) No more than a trace of gum shall be deposited on the test
strips outside the areas in contact with the tinfoil;
(c) The aluminum strips shall not change in weight by more than 0.05
mg./sq. cm.; and
(d) The cast iron strips shall not change in weight by more than 0.3
mg./sq. cm.
S5.1.12 Effects on cups. When brake cups are subjected to brake
fluid in accordance with S6.12--
(a) The increase in the diameter of the base of the cups shall be
not less than 0.15 mm. (0.006 inch) or more than 1.40 mm. (0.055 inch);
(b) The decrease in hardness of the cups shall be not more than 10
IRHD at 70 deg.C. (158 deg.F.) or more than 15 IRHD at 120 deg.C.
(248 deg.F.), and there shall be no increase in hardness of the cups;
and
(c) The cups shall show no disintegration as evidenced by
stickiness, blisters, or sloughing.
S5.1.13 Stroking properties. When brake fluid is tested according
to S6.13--
(a) Metal parts of the test system shall show no pitting or etching
to an extent discernible without magnification;
(b) The change in diameter of any cylinder or piston shall not
exceed 0.13 mm. (0.005 inch);
(c) The average decrease in hardness of seven of the eight cups
tested (six wheel cylinder and one master cylinder primary) shall not
exceed 15 IRHD. Not more than one of the seven cups shall have a
decrease in hardness greater than 17 IRHD;
(d) None of the eight cups shall be in an unsatisfactory operating
condition as evidenced by stickiness, scuffing, blisters, cracking,
chipping, or other change in shape from its original appearance;
(e) None of the eight cups shall show an increase in base diameter
greater than 0.90 mm (0.035 inch);
(f) The average lip diameter set of the eight cups shall not be
greater than 65 percent.
(g) During any period of 24,000 strokes, the volume loss of fluid
shall not exceed 36 milliliters;
(h) The cylinder pistons shall not freeze or function improperly
throughout the test;
(i) The total loss of fluid during the 100 strokes at the end of the
test shall not exceed 36 milliliters;
(j) The fluid at the end of the test shall show no formation of
gels;
(k) At the end of the test the amount of sediment shall not exceed
1.5 percent by volume; and
(l) Brake cylinders shall be free of deposits that are abrasive or
that cannot be removed when rubbed moderately with a nonabrasive cloth
wetted with ethanol.
S5.1.14 Fluid color. Brake fluid and hydraulic system mineral oil
shall be of the color indicated:
DOT 3, DOT 4, and DOT 5.1 non-SBBF--colorless to amber.
DOT 5 SBBF--purple.
Hydraulic system mineral oil--green.
S5.2 Packaging and labeling requirements for motor vehicle brake
fluids.
S5.2.1 Container sealing. Each brake fluid or hydraulic system
mineral oil container with a capacity of 177 mL or more shall be
provided with a resealable closure that has an inner seal impervious to
the packaged brake fluid. The container closure shall include a tamper-
proof feature that will either be destroyed or substantially altered
[[Page 337]]
when the container closure is initially opened.
S5.2.2 Certification, marking, and labeling.
S5.2.2.1 Each manufacturer of a DOT grade brake fluid shall furnish
to each packager, distributor, or dealer to whom he delivers brake
fluid, the following information:
(a) A serial number identifying the production lot and the date of
manufacture of the brake fluid.
(b) The grade (DOT 3, DOT 4, DOT 5) of the brake fluid. If DOT 5
grade brake fluid , it shall be further distinguished as ``DOT 5
SILICONE BASE'' or ``DOT 5.1 NON-SILICONE BASE.''
(c) The minimum wet boiling point in Fahrenheit of the brake fluid.
(d) Certification that the brake fluid conforms to Sec. 571.116.
S5.2.2.2 Each packager of brake fluid shall furnish the information
specified in paragraphs (a) through (g) of this S5.2.2.2 by clearly
marking it on each brake fluid container or on a label (labels)
permanently affixed to the container, in any location except a removable
part such as a lid. After being subjected to the operations and
conditions specified in S6.14, the information required by this section
shall be legible to an observer having corrected visual acuity of 20/40
(Snellen ratio) at a distance of 305 mm, and any label affixed to the
container in compliance with this section shall not be removable without
its being destroyed or defaced.
(a) Certification that the brake fluid conforms to Sec. 571.116.
(b) The name of the packager of the brake fluid, which may be in
code form.
(c) The name and complete mailing address of the distributor.
(d) A serial number identifying the packaged lot and date of
packaging.
(e) Designation of the contents as ``DOT--MOTOR VEHICLE BRAKE
FLUID'' (Fill in DOT 3, DOT 4, DOT 5 SILICONE BASE, or DOT 5.1 NON-
SILICONE BASE as applicable).
(f) The minimum wet boiling point in Fahrenheit of the DOT brake
fluid in the container.
(g) The following safety warnings in capital and lower case letters
as indicated:
(1) FOLLOW VEHICLE MANUFACTURER'S RECOMMENDATIONS WHEN ADDING BRAKE
FLUID.
(2) KEEP BRAKE FLUID CLEAN AND DRY. Contamination with dirt, water,
petroleum products or other materials may result in brake failure or
costly repairs.
(3) STORE BRAKE FLUID ONLY IN ITS ORIGINAL CONTAINER. KEEP CONTAINER
CLEAN AND TIGHTLY CLOSED TO PREVENT ABSORPTION OF MOISTURE.
(4) CAUTION: DO NOT REFILL CONTAINER, AND DO NOT USE FOR OTHER
LIQUIDS. (Not required for containers with a capacity in excess of 19
L.)
S5.2.2.3 Each packager of hydraulic system mineral oil shall
furnish the information specified in paragraphs (a) through (e) of this
S5.2.2.3 by clearly marking it on each brake fluid container or on a
label (labels) permanently affixed to the container, in any location
except a removable part such as a lid. After being subjected to the
operations and conditions specified in S6.14, the information required
by this section shall be legible to an observer having corrected visual
acuity of 20/40 (Snellen ratio) at a distance of 305 mm and any label
affixed to the container in compliance with this section shall not be
removable without its being destroyed or defaced.
(a) The name of the packager of the hydraulic system mineral oil,
which may be in code form.
(b) The name and complete mailing address of the distributor.
(c) A serial number identifying the packaged lot and date of
packaging.
(d) Designation of the contents as ``HYDRAULIC SYSTEM MINERAL OIL''
in capital letters at least 3 mm high.
(e) The following safety warnings in capital and lower case letters
as indicated:
(1) FOLLOW VEHICLE MANUFACTURER'S RECOMMENDATIONS WHEN ADDING
HYDRAULIC SYSTEM MINERAL OIL.
(2) Hydraulic System Mineral Oil is NOT COMPATIBLE with the rubber
components of brake systems designed for use with DOT brake fluids.
[[Page 338]]
(3) KEEP HYDRAULIC SYSTEM MINERAL OIL CLEAN. Contamination with dust
or other materials may result in brake failure or costly repair.
(4) CAUTION: STORE HYDRAULIC SYSTEM MINERAL OIL ONLY IN ITS ORIGINAL
CONTAINER. KEEP CONTAINER CLEAN AND TIGHTLY CLOSED. DO NOT REFILL
CONTAINER OR USE OTHER LIQUIDS. (The last sentence is not required for
containers with a capacity in excess of 19 L.)
S5.2.2.4 If a container for brake fluid or hydraulic system mineral
oil is not normally visible but designed to be protected by an outer
container or carton during use, the outer container or carton rather
than the inner container shall meet the labeling requirements of
S5.2.2.2 or S5.2.2.3, as appropriate.
S5.3 Motor vehicle requirement. Each passenger car, multipurpose
passenger vehicle, truck, bus, trailer, and motorcycle that has a
hydraulic brake system shall be equipped with fluid that has been
manufactured and packaged in conformity with the requirements of this
standard.
S6. Test procedures.
S6.1 Equilibrium reflux boiling point. Determine the ERBP of a
brake fluid by running duplicate samples according to the following
procedure and averaging the results.
S6.1.1 Summary of procedure. Sixty milliliters (ml.) of brake fluid
are boiled under specified equilibrium conditions (reflux) at
atmospheric pressure in a 100-ml. flask. The average temperature of the
boiling fluid at the end of the reflux period, corrected for variations
in barometric pressure if necessary, is the ERBP.
S6.1.2 Apparatus. (See Figure 1) The test apparatus shall consist
of--
(a) Flask. (See Figure 2) A 100-ml. round-bottom, short-neck heat-
resistant glass flask having a neck with a \19/38\ standard taper,
female ground-glass joint and a side-entering tube, with an outside
diameter of 10 millimeters (mm.), which centers the thermometer bulb in
the flask 6.5 mm. from the bottom;
(b) Condenser. A water-cooled, reflux, glass-tube type, condenser
having a jacket 200 mm. in length, the bottom end of which has a \19/38\
standard-taper, drip-tip, male ground-glass joint;
(c) Boiling stones. Three clean, unused silicon carbide grains
(approximately 2 mm. (0.08 inch) in diameter, grit No. 8);
(d) Thermometer. Standardized calibrated partial immersion (76 mm.),
solid stem, thermometers conforming to the requirements for an ASTM 2C
or 2F, and an ASTM 3C or 3F thermometer; and
(e) Heat source. Variable autotransformer-controlled heating mantle
designed to fit the flask, or an electric heater with rheostat heat
control.
[GRAPHIC] [TIFF OMITTED] TC01AU91.043
Fig. 1. Boiling Point Test Apparatus
[[Page 339]]
[GRAPHIC] [TIFF OMITTED] TC01AU91.044
Fig. 2. Detail of 100 ml Short-Neck Flask
S6.1.3 Preparation of apparatus. (a) Thoroughly clean and dry all
glassware.
(b) Insert thermometer through the side tube until the tip of the
bulb is 6.5 mm. (\1/4\ inch) from the bottom center of the flask. Seal
with a short piece of natural rubber, EPDM, SBR, or butyl tubing.
(c) Place 601 ml. of brake fluid and the silicon carbide
grains into the flask.
(d) Attach the flask to the condenser. When using a heating mantle,
place the mantle under the flask and support it with a ring-clamp and
laboratory-type stand, holding the entire assembly in place by a clamp.
When using a rheostat-controlled heater, center a standard porcelain or
hard asbestos refractory, having a diameter opening 32 to 38 mm., over
the heating element and mount the flask so that direct heat is applied
only through the opening in the refractory. Place the assembly in an
area free from drafts or other types of sudden temperature changes.
Connect the cooling water inlet and outlet tubes to the condenser. Turn
on the cooling water. The water supply temperature shall not exceed 28
deg.C. (82.4 deg.F.) and the temperature rise through the condenser
shall not exceed 2 deg.C. (3.6 deg.F.).
S6.1.4 Procedure. Apply heat to the flask so that within
102 minutes the fluid is refluxing in excess of 1 drop per
second. The reflux rate shall not exceed 5 drops per second at any time.
Immediately adjust the heating rate to obtain an equilibrium reflux rate
of 1 to 2 drops per second over the next 52 minutes.
Maintain this rate for an additional 2 minutes, taking four temperature
readings at 30-second intervals. Record the average of these as the
observed ERBP. If no reflux is evident when the fluid temperature
reaches 260 deg.C (500 deg.F), discontinue heating and report ERBP as
in excess of 260 deg.C (500 deg.F).
S6.1.5 Calculation. (a) Thermometer inaccuracy. Correct the
observed ERBP by applying any correction factor obtained in
standardizing the thermometer.
(b) Variation from standard barometric pressure. Apply the factor
shown in Table III to calculate the barometric pressure correction to
the ERBP.
Table III--Correction for Barometric Pressure
------------------------------------------------------------------------
Correction per 1 mm
difference in
Observed ERBP corrected for thermometer pressurea
inaccuracy -----------------------
deg.C. ( deg.F.)
------------------------------------------------------------------------
100 deg.C. (212 deg.F.) to 190 deg.C. (374 0.039 (0.07)
deg.F.)........................................
Over 190 deg.C. (374 deg.F.).................. 0.04 (0.08)
------------------------------------------------------------------------
a To be added in case barometric pressure is below 760 mm.; to be
subtracted in case barometric pressure is above 670 mm.
(c) If the two corrected observed ERBP's agree within 2 deg.C. (4
deg.C. for brake fluids having an ERBP over 230 deg.C./446 deg.F.)
average the duplicate runs as the ERBP; otherwise, repeat the entire
test, averaging the four corrected observed values to determine the
original ERBP.
S6.2 Wet ERBP. Determine the wet ERBP of a brake fluid by running
duplicate samples according to the following procedure.
S6.2.1. Summary of procedure. A 350 ml. sample of the brake fluid
is humidified under controlled conditions; 350 ml. of SAE triethylene
glycol monomethyl ether, brake fluid grade, referee material (TEGME) as
described in appendix E of SAE Standard J1703 Nov. 83, ``Motor Vehicle
Brake Fluid,'' November 1983, is used to establish the end point for
humidification. After humidification, the water content and
[[Page 340]]
ERBP of the brake fluid are determined.
S6.2.2 Apparatus for humidification. (See Figure 3).
Test apparatus shall consist of--
(a) Glass jars. Four SAE RM-49 corrosion test jars or equivalent
screwtop, straight-sided, round glass jars each having a capacity of
about 475 ml. and approximate inner dimensions of 100 mm. in height by
75 mm. in diameter, with matching lids having new, clean inserts
providing water-vapor-proof seals;
(b) Desiccator and cover. Two bowl-form glass desiccators, 250-mm.
inside diameter, having matching tubulated covers fitted with No. 8
rubber stoppers; and
(c) Desiccator plate. Two 230-mm. diameter, perforated porcelain
desiccator plates, without feet, glazed on one side.
S6.2.3 Reagents and materials. (a) Distilled water, see S7.1.
(b) SAE TEGME referee material.
S6.2.4 Preparation of apparatus. Lubricate the ground-glass joint
of the desiccator. Pour 45010 ml. of distilled water into
each desiccator and insert perforated porcelain desiccator plates. Place
the desiccators in an oven with temperature controlled at
501 deg.C. (1221.8 deg.F.) throughout the
humidification procedure.
S6.2.5 Procedure. Pour 3505 ml. of brake fluid into an
open corrosion test jar. Prepare in the same manner a duplicate test
fluid sample and two duplicate specimens of the SAE TEGME referee
material (3505 ml. of TEGME in each jar). The water content
of the SAE TEGME fluid is adjusted to 0.500.05 percent by
weight at the start of the test in accordance with S7.2. Place one
sample each of the test brake fluid and the prepared TEGME sample into
the same desiccator. Repeat for the second sample of test brake fluid
and TEGME in a second desiccator. Place the desiccators in the 50
deg.C. (122 deg.F.) controlled oven and replace desiccator covers. At
intervals, during oven humidification, remove the rubber stoppers in the
tops of desiccators. Using a long needled hypodermic syringe, take a
sample of not more than 2 ml. from each TEGME sample and determine its
water content. Remove no more than 10 ml. of fluid from each SAE TEGME
sample during the humidification procedure. When the water content of
the SAE fluid reaches 3.700.05 percent by weight (average of
the duplicates). remove the two test fluid specimens from their
desiccators and promptly cap each jar tightly. Allow the sealed jars to
cool for 60 to 90 minutes at 23 deg.5 deg.C.
(73.4 deg.9 deg.F.). Measure the water contents of the test
fluid specimens in accordance with S7.2 and determine their ERBP's in
accordance with S6.1. If the two ERBPs agree within 4 deg.C. (8
deg.F.), average them to determine the wet ERBP; otherwise repeat and
average the four individual ERBPs as the wet ERBP of the brake fluid.
[[Page 341]]
[GRAPHIC] [TIFF OMITTED] TC01AU91.045
S6.3 Kinematic viscosities. Determine the kinematic viscosity of a
brake fluid in mm2/s by the following procedure. Run
duplicate samples at each of the specified temperatures, making two
timed runs on each sample.
S6.3.1 Summary of the procedure. The time is measured for a fixed
volume of the brake fluid to flow through a calibrated glass capillary
viscometer under an accurately reproducible head and at a closely
controlled temperature. The kinematic viscosity is then calculated from
the measured flow time and the calibration constant of the viscometer.
S6.3.2 Apparatus.
(a) Viscometers. Calibrated glass capillary-type viscometers, ASTM
D2515-66, ``Standard Specification for Kinematic Glass Viscometers,''
measuring viscosity within the precision limits of S6.4.7. Use suspended
level viscometers for viscosity measurements at low temperatures. Use
Cannon-Fenske Routine or other modified Ostwald viscometers at ambient
temperatures and above.
(b) Viscometer holders and frames. Mount a viscometer in the
constant-temperature bath so that the mounting tube is held within
1 deg. of the vertical.
(c) Viscometer bath. A transparent liquid bath of sufficient depth
such that
[[Page 342]]
at no time during the measurement will any portion of the sample in the
viscometer be less than 2 cm. below the surface or less than 2 cm. above
the bottom. The bath shall be cylindrical in shape, with turbulent
agitation sufficient to meet the temperature control requirements. For
measurements within 15 deg. to 100 deg.C. (60 deg. to 212 deg.F.) the
temperature of the bath medium shall not vary by more than 0.01 deg.C.
(0.02 deg.F.) over the length of the viscometers, or between the
positions of the viscometers, or at the locations of the thermometers.
Outside this range, the variation shall not exceed 0.03 deg.C. (0.05
deg.F.).
(d) Thermometers. Liquid-in-Glass Kinematic Viscosity Test
Thermometers, covering the range of test temperatures indicated in Table
IV and conforming to ASTM E1-68, ``Specifications for ASTM
Thermometers,'' and in the IP requirements for IP Standard Thermometers.
Standardize before use (see S6.3.3(b)). Use two standardized
thermometers in the bath.
Table IV--Kinematic Viscosity Thermometers
--------------------------------------------------------------------------------------------------------------------------------------------------------
Temperature range For tests at Subdivisions Thermometer number
--------------------------------------------------------------------------------------------------------------------------------------------------------
deg.C. deg.F. deg.C. deg.F. deg.C. deg.F. ASTM IP
--------------------------------------------------------------------------------------------------------------------------------------------------------
Minus 55.3 to minus 52.5........... Minus 67.5 to minus Minus 55............. Minus 67............. 0.05 0.1 74 F 69 F. or C.
62.5.
Minus 41.4 to minus 38.6........... Minus 42.5 to minus Minus 40............. Minus 40............. 0.05 0.1 73 F 68 F. or C.
37.5.
98.6 to 101.4...................... 207.5 to 212.5....... 100.................. 212.................. 0.05 0.1 30 F 32 F. or C.
--------------------------------------------------------------------------------------------------------------------------------------------------------
(e) Timing device. Stop watch or other timing device graduated in
divisions representing not more than 0.2 second, with an accuracy of at
least 0.05 percent when tested over intervals of 15 minutes.
Electrical timing devices may be used when the current frequency is
controlled to an accuracy of 0.01 percent or better.
S6.3.3 Standardization.
(a) Viscometers. Use viscometers calibrated in accordance with
appendix 1 of ASTM D445-65, ``Viscosity of Transparent and Opaque
Liquids (Kinematic and Dynamic Viscosities).'' The calibration constant,
C, is dependent upon the gravitational acceleration at the place of
calibration. This must, therefore, be supplied by the standardization
laboratory together with the instrument constant. Where the acceleration
of gravity, g, in the two locations differs by more than 0.1 percent,
correct the calibration constant as follows:
C2=(g2/g1)xC1
where the subscripts 1 and 2 indicate respectively the
standardization laboratory and the testing laboratory.
(b) Thermometers. Check liquid-in-glass thermometers to the nearest
0.01 deg.C. (0.02 deg.F.) by direct comparison with a standardized
thermometer. Kinematic Viscosity Test Thermometers shall be standardized
at ``total immersion.'' The ice point of standardized thermometers shall
be determined before use and the official corrections shall be adjusted
to conform to the changes in ice points. (See ASTM E77-66,
``Verification and Calibration of Liquid-in-Glass Thermometers.'')
(c) Timers. Time signals are broadcast by the National Bureau of
Standards, Station WWV, Washington, DC at 2.5, 5, 10, 15, 20, 25, 30,
and 35 Mc/sec (MHz). Time signals are also broadcast by Station CHU from
Ottawa, Canada, at 3.330, 7.335, and 14.670 Mc/sec, and Station MSF at
Rugby, United Kingdom, at 2.5, 5, and 10 Mc/sec.
S6.3.4 Procedure. (a) Set and maintain the bath at the appropriate
test temperature (see S5.1.3) within the limits specified in S6.3.2(c).
Apply the necessary corrections, if any, to all thermometer readings.
(b) Select a clean, dry, calibrated viscometer giving a flow time
not less than its specified minimum, or 200 seconds, whichever is the
greater.
(c) Charge the viscometer in the manner used when the instrument was
calibrated. Do not filter or dry the brake fluid, but protect it from
contamination by dirt and moisture during filling and measurements.
(1) Charge the suspended level viscometers by tilting about 30 deg.
from
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the vertical and pouring sufficient brake fluid through the fill tube
into the lower reservoir so that when the viscometer is returned to
vertical position the meniscus is between the fill marks. For
measurements below 0 deg.C. (32 deg.F.), before placing the filled
viscometer into the constant temperature bath, draw the sample into the
working capillary and timing bulb and insert small rubber stoppers to
suspend the fluid in this position, to prevent accumulation of water
condensate on the walls of the critical portions of the viscometer.
Alternatively, fit loosely packed drying tubes into the open ends of the
viscometer to prevent water condensation, but do not restrict the flow
of the sample under test by the pressures created in the instrument.
(2) If a Cannon-Fenske Routine viscometer is used, charge by
inverting and immersing the smaller arm into the brake fluid and
applying vacuum to the larger arm. Fill the tube to the upper timing
mark, and return the viscometer to an upright position.
(d) Mount the viscometer in the bath in a true vertical position
(see S6.3.2(b)).
(e) The viscometer shall remain in the bath until it reaches the
test temperature.
(f) At temperatures below 0 deg.C. (32 deg.F.) conduct an untimed
preliminary run by allowing the brake fluid to drain through the
capillary into the lower reservoir after the test temperature has been
established.
(g) Adjust the head level of the brake fluid to a position in the
capillary arm about 5 mm. above the first timing mark.
(h) With brake fluid flowing freely measure to within 0.2 second the
time required for the meniscus to pass from the first timing mark to the
second. If this flow time is less than the minimum specified for the
viscometer, or 200 seconds, whichever is greater, repeat using a
viscometer with a capillary of smaller diameter.
(i) Repeat S6.3.4 (g) and (h). If the two timed runs do not agree
within 0.2 percent, reject and repeat using a fresh sample of brake
fluid.
S6.3.5 Cleaning the viscometers. (a) Periodically clean the
instrument with chromic acid to remove organic deposits. Rinse
thoroughly with distilled water and acetone, and dry with clean dry air.
(b) Between successive samples rinse the viscometer with ethanol
(isopropanol when testing DOT 5 fluids) followed by an acetone or ether
rinse. Pass a slow stream of filtered dry air through the viscometer
until the last trace of solvent is removed.
S6.3.6 Calculation. (a) The following viscometers have a fixed
volume charged at ambient temperature, and as a consequence C varies
with test temperature: Cannon-Fenske Routine, Pinkevitch, Cannon-Manning
Semi-Micro, and Cannon Fenske Opaque. To calculate C at test
temperatures other than the calibration temperature for these
viscometers, see ASTM D2515-66, ``Kinematic Glass Viscometers'' or
follow instructions given on the manufacturer's certificate of
calibration.
(b) Average the four timed runs on the duplicate samples to
determine the kinematic viscosities.
S6.3.7 Precision (at 95 percent confidence level).
(a) Repeatability. If results on duplicate samples by the same
operator differ by more than 1 percent of their mean, repeat the tests.
S6.4 pH value. Determine the pH value of a brake fluid by running
one sample according to the following procedure.
S6.4.1 Summary of the procedure. Brake fluid is diluted with an
equal volume of an ethanol-water solution. The pH of the resultant
mixture is measured with a prescribed pH meter assembly at 23 deg.C.
(73.4 deg.F.).
S6.4.2 Apparatus. The pH assembly consists of the pH meter, glass
electrode, and calomel electrode, as specified in Appendices A1.1, A1.2,
and A1.3 of ASTM D 1121-67, ``Standard Method of Test for Reserve
Alkalinity of Engine Antifreezes and Antirusts.'' The glass electrode is
a full range type (pH 0-14), with low sodium error.
S6.4.3 Reagents. Reagent grade chemicals conforming to the
specifications of the Committee on Analytical Reagents of the American
Chemical Society.
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(a) Distilled water. Distilled water (S7.1) shall be boiled for
about 15 minutes to remove carbon dioxide, and protected with a soda-
lime tube or its equivalent while cooling and in storage. (Take
precautions to prevent contamination by the materials used for
protection against carbon dioxide.) The pH of the boiled distilled water
shall be between 6.2 and 7.2 at 25 deg.C. (77 deg.F.).
(b) Standard buffer solutions. Prepare buffer solutions for
calibrating the pH meter and electrode pair from salts sold specifically
for use, either singly or in combination, as pH standards. Dry salts for
1 hour at 110 deg.C. (230 deg.F.) before use except for borax which
shall be used as the decahydrate. Store solutions with pH less than 9.5
in bottles of chemically resistant glass or polyethylene. Store the
alkaline phosphate solution in a glass bottle coated inside with
paraffin. Do not use a standard with an age exceeding three months.
(1) Potassium hydrogen phthalate buffer solution (0.05 M, pH=4.01 at
25 deg.C. (77 deg.F.)). Dissolve 10.21 g. of potassium hydrogen
phthalate (KHC8 H4 O4) in distilled
water. Dilute to 1 liter.
(2) Neutral phosphate buffer solution (0.025 M with respect to each
phosphate salt, pH=6.86 at 25 deg.C. (77 deg.F.)). Dissolve 3.40 g. of
potassium dihydrogen phosphate (KH2 PO4) and 3.55
g. of anhydrous disodium hydrogen phosphate (Na2
HPO4) in distilled water.
(3) Borax buffer solution (0.01 M, pH=9.18 at 25 deg.C. (77
deg.F.)). Dissolve 3.81 g. of disodium tetraborate decahydrate (Na2
B4 O7 deg.10H2 O) in distilled water, and dilute
to 1 liter. Stopper the bottle except when actually in use.
(4) Alkaline phosphate buffer solution (0.01 M trisodium phosphate,
pH=11.72 at 25 deg.C. (77 deg.F.)). Dissolve 1.42 g. of anhydrous
disodium hydrogen phosphate (Na2 HPO4) in 100 ml.
of a 0.1 M carbonate-free solution of sodium hydroxide. Dilute to 1
liter with distilled water.
(5) Potassium chloride electrolyte. Prepare a saturated solution of
potassium chloride (KCl) in distilled water.
(c) Ethanol-water mixture. To 80 parts by volume of ethanol (S7.3)
add 20 parts by volume of distilled water. Adjust the pH of the mixture
to 70.1 using 0.1 N sodium hydroxide (NaOH) solution. If
more than 4 ml. of NaOH solution per liter of mixture is required for
neutralization, discard the mixture.
S6.4.4 Preparation of electrode system.
(a) Maintenance of electrodes. Clean the glass electrode before
using by immersing in cold chromic-acid cleaning solution. Drain the
calomel electrode and fill with KCl electrolyte, keeping level above
that of the mixture at all times. When not in use, immerse the lower
halves of the electrodes in distilled water, and do not immerse in the
mixture for any appreciable period of time between determinations.
(b) Preparation of electrodes. Condition new glass electrodes and
those that have been stored dry as recommended by the manufacturer.
Before and after using, wipe the glass electrode thoroughly with a clean
cloth, or a soft absorbent tissue, and rinse with distilled water.
Before each pH determination, soak the prepared electrode in distilled
water for at least 2 minutes. Immediately before use, remove any excess
water from the tips of the electrode.
S6.4.5 Standardization of the pH assembly and testing of the
electrodes. (a) Immediately before use, standardize the pH assembly with
a standard buffer solution. Then use a second standard buffer solution
to check the linearity of the response of the electrodes at different pH
values, and to detect a faulty glass electrode or incorrect temperature
compensation. The two buffer solutions bracket the anticipated pH value
of the test brake fluid.
(b) Allow instrument to warm up, and adjust according to the
manufacturer's instructions. Immerse the tips of the electrodes in a
standard buffer solution and allow the temperature of the buffer
solution and the electrodes to equalize. Set the temperature knob at the
temperature of the buffer solution. Adjust the standardization or
asymmetry potential control until the meter registers a scale reading,
in pH units, equal to the known pH of the standardizing buffer solution.
(c) Rinse the electrodes with distilled water and remove excess
water from the tips. Immerse the electrodes in a second standard buffer
solution. The reading of the meter shall agree with the known pH of the
second standard
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buffer solution within 0.05 unit without changing the
setting of the standardization of asymmetry potential control.
(d) A faulty electrode is indicated by failure to obtain a correct
value for the pH of the second standard buffer solution after the meter
has been standardized with the first.
S6.4.6 Procedure. To 501 ml. of the test brake fluid
add 501 ml. of the ethanol-water (S6.4.3(c)) and mix
thoroughly. Immerse the electrodes in the mixture. Allow the system to
come to equilibrium, readjust the temperature compensation if necessary,
and take the pH reading.
S6.5 Fluid stability. Evaluate the heat and chemical stability of a
brake fluid by the following procedure, running duplicate samples for
each test and averaging the results.
S6.5.1 Summary of the procedure. The degradation of the brake fluid
at elevated temperature, alone or in a mixture with a reference fluid,
is evaluated by determining the change in boiling point after a period
of heating under reflux conditions.
S6.5.2 Apparatus. Use the apparatus and preparation specified in
S6.1.2 and S6.1.3.
S6.5.3 High temperature stability.
S6.5.3.1 Procedure. (a) Heat a new 601 ml. sample of
the brake fluid to 185 deg.2 deg.C.
(365 deg.3.6 deg.F.). Hold at this temperature for
1205 minutes. Bring to a reflux rate in excess of 1 drop per
second within 5 minutes. The reflux rate should not exceed 5 drops per
second at any time. Over the next 52 minutes adjust the
heating rate to obtain an equilibrium reflux rate of 1 to 2 drops per
second. Maintain this rate for an additional 2 minutes, taking four
temperature readings at 30-second intervals. Average these as the
observed ERBP. If no reflux is evident when the fluid temperature
reaches 260 deg.C. (500 deg.F), discontinue heating and report ERBP as
in excess of 260 deg.C. (500 deg.F.).
S6.5.3.2 Calculation. Correct the observed ERBP for thermometer and
barometric pressure factors according to S6.1.5 (a) and (b). Average the
corrected ERBP's of the duplicate samples. The difference between this
average and the original ERBP obtained in S6.1 is the change in ERBP of
the fluid.
S6.5.4 Chemical stability.
S6.5.4.1 Materials. SAE RM-66-04 Compatibility Fluid as described
in appendix B of SAE Standard J1703 JAN 1995, ``Motor Vehicle Brake
Fluid.'' (SAE RM-66-03 Compatibility Fluid as described in appendix A of
SAE Standard J1703 Nov83, ``Motor Vehicle Brake Fluid,'' November 1983,
may be used in place of SAE RM-66-04 until January 1, 1995.)
S6.5.4.2 Procedure. (a) Mix 30 1 ml. of the brake
fluid with 30 1 ml. of SAE RM-66-04 Compatibility Fluid in
a boiling point flask (S6.1.2(a)). Determine the initial ERBP of the
mixture by applying heat to the flask so that the fluid is refluxing in
10 2 minutes at a rate in excess of 1 drop per second, but
not more than 5 drops per second. Note the maximum fluid temperature
observed during the first minute after the fluid begins refluxing at a
rate in excess of 1 drop per second. Over the next 15 1
minutes, adjust and maintain the reflux rate at 1 to 2 drops per second.
Maintain this rate for an additional 2 minutes, recording the average
value of four temperature readings taken at 30 second intervals as the
final ERBP.
(b) Thermometer and barometric corrections are not required.
S6.5.4.3 Calculation. The difference between the initial ERBP and
the final average temperature is the change in temperature of the
refluxing mixture. Average the results of the duplicates to the nearest
0.5 deg.C (1.0 deg.F).
S6.6 Corrosion. Evaluate the corrosiveness of a brake fluid by
running duplicate samples according to the following procedure.
S6.6.1 Summary of the procedure. Six specified metal corrosion test
strips are polished, cleaned, and weighed, then assembled as described.
Assembly is placed on a standard wheel cylinder cup in a corrosion test
jar, immersed in the water-wet brake fluid, capped and placed in an oven
at 100 deg.C. (212 deg.F.) for 120 hours. Upon removal and cooling,
the strips, fluid, and cups are examined and tested.
S6.6.2 Equipment. (a) Balance. An analytical balance having a
minimum capacity of 50 grams and capable of weighing to the nearest 0.1
mg.
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(b) Desiccators. Desiccators containing silica gel or other suitable
desiccant.
(c) Oven. Gravity convection oven capable of maintaining the desired
set point within 2 deg.C. (3.6 deg.F.).
(d) Micrometer. A machinist's micrometer 25 to 50 mm. (1 to 2
inches) capacity, or an optical comparator, capable of measuring the
diameter of the SBR wheel cylinder (WC) cups to the nearest 0.02 mm.
(0.001 inch).
S6.6.3 Materials. (a) Corrosion test strips. Two sets of strips
from each of the metals listed in appendix C of SAE Standard J1703b.
Each strip shall be approximately 8 cm. long, 1.3 cm. wide, not more
than 0.6 cm. thick, and have a surface area of 255 sq. cm.
and a hole 4 to 5 mm. (0.16 to 0.20 inch) in diameter on the centerline
about 6 mm. from one end. The hole shall be clean and free from burrs.
Tinned iron strips shall be unused. Other strips, if used, shall not be
employed if they cannot be polished to a high finish.
(b) SBR cups. Two unused standard SAE SBR wheel cylinder (WC) cups,
as specified in S7.6.
(c) Corrosion test jars and lids. Two screw-top straight-sided round
glass jars, each having a capacity of approximately 475 ml. and inner
dimensions of approximately 100 mm. in height and 75 mm. in diameter,
and a tinned steel lid (no insert or organic coating) vented with a hole
0.80.1 mm. (0.0310.004 inch) in diameter (No. 68
drill).
(d) Machine screws and nuts. Clean, rust and oil-free, uncoated mild
steel round or fillister head machine screws, size 6 or 8-32 UNC-Class
2A, five-eighths or three-fourths inch long (or equivalent metric
sizes), and matching uncoated nuts.
(e) Supplies for polishing strips. Waterproof silicon carbide paper,
grit No. 320 A; grade 00 steel wool, lint-free polishing cloth.
(f) Distilled water as specified in S7.1.
(g) Ethanol as specified in S7.3.
(h) Isopropanol as specified in S7.7.
S6.6.4 Preparation.
(a) Corrosion test strips. Except for the tinned iron strips, abrade
corrosion test strips on all surface areas with silicon carbide paper
wet with ethanol (isopropanol when testing DOT 5 SBBF fluids) until all
surface scratches, cuts and pits are removed. Use a new piece of paper
for each different type of metal. Polish the strips with the 00 grade
steel wool. Wash all strips, including the tinned iron and the assembly
hardware, with ethanol (isopropanol when testing DOT 5 SBBF fluids); dry
the strips and assembly hardware with a clean lint free cloth or use
filtered compressed air and place the strips and hardware in a
desiccator containing silica gel or other suitable desiccant and
maintained at 23 deg.5 deg.C. (73.4 deg.9
deg.F.), for at least 1 hour. Handle the strips with forceps after
polishing. Weigh and record the weight of each strip to the nearest 0.1
mg. Assemble the strips on a clean dry machine screw, with matching
plain nut, in the order of tinned iron, steel, aluminum, cast iron,
brass, and copper. Bend the strips, other than the cast iron, so that
there is a separation of 3\1/2\ mm. (\1/8\\1/64\
inch) between adjacent strips for a distance of about 5 cm. (2 inches)
from the free end of the strips. (See Figure 4.) Tighten the screw on
each test strip assembly so that the strips are in electrolytic contact,
and can be lifted by either of the outer strips (tinned iron or copper)
without any of the strips moving relative to the others when held
horizontally. Immerse the strip assemblies in 90 percent ethyl alcohol.
Dry with dried filtered compressed air, then desiccate at least 1 hour
before use.
[GRAPHIC] [TIFF OMITTED] TC01AU91.046
Fig. 4. Corrosion Strip Assembly
(b) SBR WC cups. Measure the base diameters of the two standard SBR
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cups, using an optical comparator or micrometer, to the nearest 0.02 mm.
(0.001 inch) along the centerline of the SAE and rubber-type
identifications and at right angles to this centerline. Take the
measurements at least 0.4 mm. (0.015 inch) above the bottom edge and
parallel to the base of the cup. Discard any cup if the two measured
diameters differ by more than 0.08 mm. (0.003 inch). Average the two
readings on each cup. Determine the hardness of the cups according to
S7.4.
S6.6.5 Procedure. Rinse the cups in ethanol (isopropanol when
testing DOT 5 SBBF fluids) for not more than 30 seconds and wipe dry
with a clean lint-free cloth. Place one cup with lip edge facing up, in
each jar. Insert a metal strip assembly inside each cup with the
fastened end down and the free end extending upward. (See Figure 5.)
When testing brake fluids, except DOT 5 SBBF, mix 760 ml. of brake fluid
with 40 ml. of distilled water. When testing DOT 5 SBBF's, humidify 800
ml. of brake fluid in accordance with S6.2, eliminating determination of
the ERBP. Using this water-wet mixture, cover each strip assembly to a
minimum depth of 10 mm. above the tops of the strips. Tighten the lids
and place the jars for 1202 hours in an oven maintained at
100 deg.2 deg.C. (212 deg.3.6 deg.F.). Allow
the jars to cool at 23 deg.5 deg.C. (73.4 deg.9
deg.F.) for 60 to 90 minutes. Immediately remove the strips from the
jars using forceps, agitating the strip assembly in the fluid to remove
loose adhering sediment. Examine the test strips and jars for adhering
crystalline deposits. Disassemble the metal strips, and remove adhering
fluid by flushing with water; clean each strip by wiping with a clean
cloth wetted with ethanol (isopropanol when testing DOT 5 fluids).
Examine the strips for evidence of corrosion and pitting. Disregard
staining or discoloration. Place the strips in a desiccator containing
silica gel or other suitable desiccant, maintained at
23 deg.5 deg.C. (73.4 deg.9 deg.F.), for at
least 1 hour. Weigh each strip to the nearest 0.1 mg. Determine the
change in weight of each metal strip. Average the results for the two
strips of each type of metal. Immediately following the cooling period,
remove the cups from the jars with forceps. Remove loose adhering
sediment by agitation of the cups in the mixture. Rinse the cups in
ethanol (isopropanol when testing DOT 5 fluids) and air-dry. Examine the
cups for evidence of sloughing, blisters, and other forms of
disintegration. Measure the base diameter and hardness of each cup
within 15 minutes after removal from the mixture. Examine the mixture
for gelling. Agitate the mixture to suspend and uniformly disperse
sediment. From each jar, transfer a 100 ml. portion of the mixture to an
ASTM cone-shaped centrifuge tube. Determine the percent sediment after
centrifuging as described in S7.5. Measure the pH value of the corrosion
text fluid according to S6.4.6. Measure the pH value of the test mixture
according to S6.4.6.
[GRAPHIC] [TIFF OMITTED] TC01AU91.047
Fig. 5. Corrosion Test Apparatus
S6.6.6 Calculation. (a) Measure the area of each type of test strip
to the nearest square centimeter. Divide the average change in mass for
each type by the area of that type.
(b) Note other data and evaluations indicating compliance with
S5.1.6. In the event of a marginal pass on inspection by attributes, or
of a failure in one of the duplicates, run another set of duplicate
samples. Both repeat samples shall meet all requirements of S5.1.6.
S6.7 Fluidity and appearance at low temperatures. Determine the
fluidity and appearance of a sample of brake fluid at each of two
selected temperatures by the following procedure.
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S6.7.1 Summary of procedure. Brake fluid is chilled to expected
minimum exposure temperatures and observed for clarity, gellation,
sediment, separation of components, excessive viscosity or thixotropy.
S6.7.2 Apparatus. (a) Oil sample bottle. Two clear flint glass 4-
ounce bottles made especially for sampling oil and other liquids, with a
capacity of approximately 125 ml., an outside diameter of
370.05 mm. and an overall height of 1652.5 mm.
(b) Cold chamber. An air bath cold chamber capable of maintaining
storage temperatures down to minus 55 deg.C. (minus 67 deg.F.) with an
accuracy of 2 deg.C. (3.6 deg.F.).
(c) Timing device. A timing device in accordance with S6.3.2(e).
S6.7.3 Procedure. (a) Place 1001 ml. of brake fluid at
room temperature in an oil sample bottle. Stopper the bottle with an
unused cork and place in the cold chamber at the higher storage
temperature specified in Table II (S5.1.7(c)). After 1444
hours remove the bottle from the chamber, quickly wipe it with a clean,
lint-free cloth, saturated with ethanol (isopropanol when testing DOT 5
fluids) or acetone. Examine the fluid for evidence of sludging,
sedimentation, crystallization, or stratification. Invert the bottle and
determine the number of seconds required for the air bubble to travel to
the top of the fluid. Let sample warm to room temperature and examine.
(b) Repeat S6.7.3(a), substituting the lower cold chamber
temperature specified in Table II, and a storage period of 6 hours
12 minutes.
Note: Test specimens from either storage temperature may be used for
the other only after warming up to room temperature.
S6.8 Evaporation. The evaporation residue, and pour point of the
evaporation residue of brake fluid, are determined by the following
procedure. Four replicate samples are run.
S6.8.1 Summary of the procedure. The volatile diluent portion of a
brake fluid is evaporated in an oven at 100 deg.C. (212 deg.F.). The
nonvolatile lubricant portion (evaporation residue) is measured and
examined for grittiness; the residues are then combined and checked to
assure fluidity at minus 5 deg.C. (23 deg.F.).
S6.8.2 Apparatus.
(a) Petri dishes. Four covered glass petri dishes approximately 100
mm. in diameter and 15 mm. in height.
(b) Oven. A top-vented gravity-convection oven capable of
maintaining a temperature of 100 deg.2 deg.C.
(212 deg.3.6 deg.F.).
(c) Balance. A balance having a capacity of at least 100 grams,
capable of weighing to the nearest 0.01 gram, and suitable for weighing
the petri dishes.
(d) Oil sample bottle. A glass sample bottle as described in
S6.7.2(a).
(e) Cold chamber. Air bath cold chamber capable of maintaining an
oil sample bottle at minus 5 deg.1 deg.C.
(23 deg.2 deg.F.).
(f) Timing device. A timing device as described in S6.3.2(e).
S6.8.3 Procedure. Obtain the tare weight of each of the four
covered petri dishes to the nearest 0.01 gram. Place 251 ml.
of brake fluid in each dish, replace proper covers and reweigh.
Determine the weight of each brake fluid test specimen by the
difference. Place the four dishes, each inside its inverted cover, in
the oven at 100 deg.2 deg.C. (212 deg.4
deg.F.) for 462 hours. (Note: Do not simultaneously heat
more than one fluid in the same oven.) Remove the dishes from the oven,
allow to cool to 23 deg.5 deg.C. (73.4 deg.9
deg.F.), and weigh. Return to the oven for an additional 242
hours. If at the end of 724 hours the average loss by
evaporation is less than 60 percent, discontinue the evaporation
procedure and proceed with examination of the residue. Otherwise,
continue this procedure either until equilibrium is reached as evidenced
by an incremental mass loss of less than 0.25 gram in 24 hours on all
individual dishes or for a maximum of 7 days. During the heating and
weighing operation, if it is necessary to remove the dishes from the
oven for a period of longer than 1 hour, the dishes shall be stored in a
desiccator as soon as cooled to room temperature. Calculate the
percentage of fluid evaporated from each dish. Examine the residue in
the dishes at the end of 1 hour at 23 deg.5 deg.C.
(73.4 deg.9 deg.F.). Rub any sediment with the fingertip to
determine grittiness or abrasiveness. Combine the residues from all four
dishes in a 118 mL (4-ounce) oil-sample bottle and store vertically in a
cold chamber at minus 5 deg.1 deg.C. (23 deg.5
deg.F.) for 6010 minutes. Quickly remove the bottle and
place in the horizontal position.
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The residue must flow at least 5 mm (0.2 inch) along the tube within 5
seconds.
S6.8.4 Calculation. The average of the percentage evaporated from
all four dishes is the loss by evaporation.
S6.9 Water tolerance. Evaluate the water tolerance characteristics
of a brake fluid by running one test specimen according to the following
procedure.
S6.9.1 Summary of the procedure.
Brake fluid, except DOT 5 SBBF, is diluted with 3.5 percent water
(DOT 5 SBBF is humidified), then stored at minus 40 deg.C. (minus 40
deg.F.) for 120 hours. The cold, water-wet fluid is first examined for
clarity, stratification, and sedimentation, then placed in an oven at 60
deg.C. (140 deg.F.) for 24 hours. On removal, it is again examined for
stratification, and the volume percent of sediment determined by
centrifuging.
S6.9.2 Apparatus.
(a) Centrifuge tube. See S7.5.1(a).
(b) Centrifuge. See S7.5.1(b).
(c) Cold chamber. See S6.7.2(b).
(d) Oven. Gravity or forced convection oven.
(e) Timing device. See S6.3.2(e).
S6.9.3 Procedure.
(a) At low temperature. Humidify 1001 ml. of DOT 5 SBBF
brake fluid in accordance with S6.2 eliminating determination of the
ERBP. When testing brake fluids except DOT 5 SBBF, mix
3.50.1 ml. of distilled water with 1001 ml. of
the brake fluid; pour into a centrifuge tube. Stopper the tube with a
clean cork and place in the cold chamber maintained at minus
402 deg.C. (minus 403.6 deg.F.). After 120
hours2 hours remove the tube, quickly wipe with clean lint-
free cloth saturated with ethanol or acetone and examine the fluid for
evidence of sludging, sedimentation, crystallization, or stratification.
Invert the tube and determine the number of seconds required for the air
bubble to travel to the top of the fluid. (The air bubble is considered
to have reached the top of the fluid when the top of the bubble reaches
the 2 ml. graduation of the centrifuge tube.) If the wet fluid has
become cloudy, warm to 235 deg.C. (73.49
deg.F.) and note appearance and fluidity.
(b) At 60 deg.C. (140 deg.F.). Place tube and brake fluid from
S6.9.3(a) in an oven maintained at 60 deg.2 deg.C.
(140 deg.3.6 deg.F.) for 242 hours. Remove the
tube and immediately examine the contents for evidence of
stratification. Determine the percent sediment by centrifuging as
described in S7.5.
S6.10 Compatibility. The compatibility of a brake fluid with other
brake fluids shall be evaluated by running one test sample according to
the following procedure.
S6.10.1 Summary of the procedure.
Brake fluid is mixed with an equal volume of SAE RM-66-04
Compatibility Fluid, then tested in the same way as for water tolerance
(S6.9) except that the bubble flow time is not measured. This test is an
indication of the compatibility of the test fluid with other motor
vehicle brake fluids at both high and low temperatures.
S6.10.2 Apparatus and materials.
(a) Centrifuge tube. See S7.5.1(a).
(b) Centrifuge. See S7.5.1(b).
(c) Cold Chamber. See S6.7.2(b)
(d) Oven. See S6.9.2(d)
(e) SAE RM-66-04 Compatibility Fluid. As described in appendix B of
SAE Standard J1703 JAN 1995 ``Motor Vehicle Brake Fluid.'' (SAE RM-66-03
Compatibility Fluid as described in appendix A of SAE Standard J1703
NOV83, ``Motor Vehicle Brake Fluid,'' November 1983, may be used in
place of SAE RM-66-04 until January 1, 1995.)
S6.10.3 Procedure.
(a) At low temperature.
Mix 500.5 mL of brake fluid with 500.5 mL of
SAE RM-66-04 Compatibility Fluid. Pour this mixture into a centrifuge
tube and stopper with a clean dry cork. Place tube in the cold chamber
maintained at minus 40 deg.2 deg.C. (minus
40 deg.4 deg.F). After 242 hours, remove tube,
quickly wipe with a clean lint-free cloth saturated with ethanol
(isopropanol when testing DOT 5 fluids) or acetone. Examine the test
specimen for evidence of slugging, sedimentation, or crystallization.
Test fluids, except DOT 5 SBBF, shall be examined for stratification.
S6.11 Resistance to oxidation. The stability of a brake fluid under
oxidative conditions shall be evaluated by running duplicate samples
according to the following procedure.
S6.11.1 Summary of procedure.
[[Page 350]]
Brake fluids, except DOT 5 SBBF, are activated with a mixture of
approximately 0.2 percent benzoyl peroxide and 5 percent water. DOT 5
SBBF is humidified in accordance with S6.2 eliminating determination of
the ERBP, and then approximately 0.2 percent benzoyl peroxide is added.
A corrosion test strip assembly consisting of cast iron and an aluminum
strip separated by tinfoil squares at each end is then rested on a piece
of SBR WC cup positioned so that the test strip is half immersed in the
fluid and oven aged at 70 deg.C. (158 deg.F.) for 168 hours. At the
end of this period, the metal strips are examined for pitting, etching,
and loss of mass.
S6.11.2 Equipment.
(a) Balance. See S6.6.2(a).
(b) Desiccators. See S6.6.2(b).
(c) Oven. See S6.6.2(c).
(d) Three glass test tubes approximately 22 mm. outside diameter by
175 mm. in length.
S6.11.3 Reagents and materials.
(a) Benzoyl peroxide, reagent grade, 96 percent. (Benzoyl peroxide
that is brownish, or dusty, or has less than 90 percent purity, must be
discarded.) Reagent strength may be evaluated by ASTM E298-68,
``Standard Methods for Assay of Organic Peroxides.''
(b) Corrosion test strips. Two sets of cast iron and aluminum metal
test strips as described in appendix C of SAE Standard J1703b.
(c) Tinfoil. Four unused pieces of tinfoil approximately 12 mm. (\1/
2\ inch) square and between 0.02 and 0.06 mm. (0.0008 and 0.0024 inch)
in thickness. The foil shall be at least 99.9 percent tin and contain
not more than 0.025 percent lead.
(d) SBR cups. Two unused, approximately one-eighth sections of a
standard SAE SBR WC cup (as described in S7.6).
(e) Machine screw and nut. Two clean oil-free, No. 6 or 8-32x\3/8\-
or \1/2\-inch long (or equivalent metric size), round or fillister head,
uncoated mild steel machine screws, with matching plain nuts.
S6.11.4 Preparation.
(a) Corrosion test strips. Prepare two sets of aluminum and cast
iron test strips according to S6.6.4(a) except for assembly. Weigh each
strip to the nearest 0.1 mg. and assemble a strip of each metal on a
machine screw, separating the strips at each end with a piece of
tinfoil. Tighten the nut enough to hold both pieces of foil firmly in
place.
(b) Test mixture.Place 301 ml. of the brake fluid under
test in a 22 by 175 mm. test tube. For all fluids except DOT 5 SBBF, add
0.060.002 grams of benzoyl peroxide, and
1.500.05 ml. of distilled water. For DOT 5 SBBF, use test
fluid humidified in accordance with S6.2, and add only the benzoyl
peroxide. Stopper the tube loosely with a clean dry cork, shake, and
place in an oven for 2 hours at 70 deg.2 deg.C.
(158 deg.3.6 deg.F.). Shake every 15 minutes to effect
solution of the peroxide, but do not wet cork. Remove the tube from the
oven and allow to cool to 23 deg.5 deg.C.
(73.4 deg.9 deg.F.) Begin testing according to paragraph
S6.11.5 not later than 24 hours after removal of tube from oven.
S6.11.5 Procedure. Place a one-eighth SBR cup section in the bottom
of each tube. Add 10 ml. of prepared test mixture to each test tube.
Place a metal-strip assembly in each, the end of the strip without the
screw resting on the rubber, and the solution covering about one-half
the length of the strips. Stopper the tubes with clean dry corks and
store upright for 702 hours at 23 deg.5 deg.C.
(73.4 deg.9 deg.F.). Loosen the corks and place the tubes
for 1682 hours in an oven maintained at 70 deg.2
deg.C. (158 deg.3.6 deg.F.). Afterwards remove and
disassemble strips. Examine the strips and note any gum deposits. Wipe
the strips with a clean cloth wet with ethanol (isopropanol when testing
DOT 5 fluids) and note any pitting, etching or roughening of surface
disregarding stain or discoloration. Place the strips in a desiccator
over silica gel or other suitable desiccant, at 23 deg.5
deg.C. (73.4 deg.9 deg.F.) for at least 1 hour. Again weigh
each strip to the nearest 0.1 mg.
S6.11.6 Calculation. Determine corrosion loss by dividing the
change in mass of each metal strip by the total surface area of each
strip measured in square millimeters (mm2), to the nearest
square millimeter (mm2). Average the results for the two
strips of each type of metal, rounding to the nearest 0.05 mg. per 100
square millimeter (mm2). If only one of the duplicates fails
for any reason, run a second set of
[[Page 351]]
duplicate samples. Both repeat samples shall meet all requirements of
S5.1.11.
S6.12 Effect on SBR cups. The effects of a brake fluid in swelling,
softening, and otherwise affecting standard SBR WC cups shall be
evaluated by the following procedure.
S6.12.1 Summary of the procedure. Four standard SAE SBR WC cups are
measured and their hardnesses determined. The cups, two to a jar, are
immersed in the test brake fluid. One jar is heated for 70 hours at 70
deg.C. (158 deg.F), and the other for 70 hours at 120 deg.C (248
deg.F). Afterwards, the cups are washed, examined for disintegration,
remeasured and their hardnesses redetermined.
S6.12.2 Equipment and supplies.
(a) Oven. See S6.6.2(c).
(b) Glass jars and lids. Two screw-top, straight-sided round glass
jars, each having a capacity of approximately 250 ml. and inner
dimensions of approximately 125 mm. in height and 50 mm. in diameter,
and a tinned steel lid (no insert or organic coating).
(c) SBR cups. See S7.6.
S6.12.3 Preparation. Measure the base diameters of the SBR cups as
described in S6.6.4(b), and the hardness of each as described in S7.4.
S6.12.4 Procedure. Wash the cups in 90 percent ethanol (isopropanol
when testing DOT 5 fluids) (see S7.3), for not longer than 30 seconds
and quickly dry with a clean, lint-free cloth. Using forceps, place two
cups into each of the two jars; add 75 ml. of brake fluid to each jar
and cap tightly. Place one jar in an oven held at 70 deg.2
deg.C. (1583.6 deg.F.) for 702 hours. Place the
other jar in an oven held at 120 deg.2 deg.C.
(248 deg.3.6 deg.F.) for 702 hours. Allow each
jar to cool for 60 to 90 minutes at 23 deg.5 deg.C.
(73.4 deg.9 deg.F.). Remove cups, wash with ethanol
(isopropanol when testing DOT 5 fluids) for not longer than 30 seconds,
and quickly dry. Examine the cups for disintegration as evidenced by
stickiness, blisters, or sloughing. Measure the base diameter and
hardness of each cup within 15 minutes after removal from the fluid.
S6.12.5 Calculation. (a) Calculate the change in base diameter for
each cup. If the two values, at each temperature, do not differ by more
than 0.10 mm. (0.004 inch) average them to the nearest 0.02 mm. (0.001
inch). If the two values differ by more than 0.10 mm., repeat the test
at the appropriate temperature and average the four values as the change
in base diameter.
(b) Calculate the change in hardness for each cup. The average of
the two values for each pair is the change in hardness.
(c) Note disintegration as evidenced by stickiness, blisters, or
sloughing.
S6.13 Stroking properties. Evaluate the lubricating properties,
component compatibility, resistance to leakage, and related qualities of
a brake fluid by running one sample according to the following
procedures.
S6.13.1 Summary of the procedure. Brake fluid is stroked under
controlled conditions at an elevated temperature in a simulated motor
vehicle hydraulic braking system consisting of three slave wheel
cylinders and an actuating master cylinder connected by steel tubing.
Referee standard parts are used. All parts are carefully cleaned,
examined, and certain measurements made immediately prior to assembly
for test. During the test, temperature, rate of pressure rise, maximum
pressure, and rate of stroking are specified and controlled. The system
is examined periodically during stroking to assure that excessive
leakage of fluid is not occurring. Afterwards, the system is torn down.
Metal parts and SBR cups are examined and remeasured. The brake fluid
and any resultant sludge and debris are collected, examined, and tested.
S6.13.2 Apparatus and equipment.
Either the drum and shoe type of stroking apparatus (see Figure 1 of
SAE Standard J1703b) except using only three sets of drum and shoe
assemblies, or the stroking fixture type apparatus as shown in Figure 2
of SAE J1703Nov83, with the components arranged as shown in Figure 1 of
SAE J1703Nov83. The following components are required.
(a) Brake assemblies. With the drum and shoe apparatus: three drum
and shoe assembly units (SAE RM-29a) consisting of three forward brake
shoes and three reverse brake shoes with linings and three front wheel
brake drum assemblies with assembly component
[[Page 352]]
parts. With stroking fixture type apparatus: three fixture units
including appropriate adapter mounting plates to hold brake wheel
cylinder assemblies.
(b) Braking pressure actuation mechanism. An actuating mechanism for
applying a force to the master cylinder pushrod without side thrust. The
amount of force applied by the actuating mechanism shall be adjustable
and capable of applying sufficient thrust to the master cylinder to
create a pressure of at least 6895 kPa (1,000 p.s.i.) in the simulated
brake system. A hydraulic gage or pressure recorder, having a range of
at least 0 to 6895 kPa (0 to 1,000 p.s.i), shall be installed between
the master cylinder and the brake assemblies and shall be provided with
a shutoff valve and with a bleeding valve for removing air from the
connecting tubing. The actuating mechanism shall be designed to permit
adjustable stroking rates of approximately 1,000 strokes per hour. Use a
mechanical or electrical counter to record the total number of strokes.
(c) Heated air bath cabinet. An insulated cabinet or oven having
sufficient capacity to house the three mounted brake assemblies or
stroking fixture assemblies, master cylinder, and necessary connections.
A thermostatically controlled heating system is required to maintain a
temperature of 70 deg.5 deg.C (158 deg.9
deg.F) or 120 deg.5 deg.C (248 deg.9 deg.F).
Heaters shall be shielded to prevent direct radiation to wheel or master
cylinder.
(d) Master cylinder (MC) assembly (SAE RM-15a). One cast iron
housing hydraulic brake system cylinder having a diameter of
approximately 28 mm. (1\1/8\ inch) and fitted for a filler cap and
standpipe (see S6.13.2(e)). The MC piston shall be made from SAE CA360
copperbase alloy (half hard). A new MC assembly is required for each
test.
(e) Filler cap and standpipe. MC filler cap provided with a glass or
uncoated steel standpipe. Standpipe must provide adequate volume for
thermal expansion, yet permit measurement and adjustment of the fluid
level in the system to 3 ml. Cap and standpipe may be
cleaned and reused.
(f) Wheel cylinder (WC) assemblies (SAE RM-14a). Three unused cast
iron housing straight bore hydraulic brake WC assemblies having
diameters of approximately 28 mm (1\1/8\ inch) for each test. Pistons
shall be made from unanodized SAE AA 2024 aluminum alloy.
(g) Micrometer. Same as S6.6.2(d).
S6.13.3 Materials.
(a) Standard SBR brake cups. Six standard SAE SBR wheel cylinder
test cups, one primary MC test cup, and one secondary MC test cup, all
as described in S7.6, for each test.
(b) Steel tubing. Double wall steel tubing meeting SAE specification
J527. A complete replacement of tubing is essential when visual
inspection indicates any corrosion or deposits on inner surface of
tubing. Tubing from master cylinder to one wheel cylinder shall be
replaced for each test (minimum length .9 m.) Uniformity in tubing size
is required between master cylinder and wheel cylinder. The standard
master cylinder has two outlets for tubing, both of which must be used.
S6.13.4 Preparation of test apparatus.
(a) Wheel cylinder assemblies. Use unused wheel cylinder assemblies.
Disassemble cylinders and discard cups. Clean all metal parts with
ethanol (isopropanol when testing DOT 5 fluids). Inspect the working
surfaces of all metal parts for scoring, galling, or pitting and
cylinder bore roughness, and discard all defective parts. Remove any
stains on cylinder walls with crocus cloth and ethanol (isopropanol when
testing DOT 5 fluids). If stains cannot be removed, discard the
cylinder. Measure the internal diameter of each cylinder at a location
approximately 19 mm. (0.75 inch) from each end of the cylinder bore,
taking measurements in line with the hydraulic inlet opening and at
right angles to this centerline. Discard the cylinder if any of these
four readings exceeds the maximum or minimum limits of 28.66 to 28.60
mm. (1.128 to 1.126 inch). Measure the outside diameter of each piston
at two points approximately 90 deg. apart. Discard any piston if either
reading exceeds the maximum or minimum limits of 28.55 to 28.52 mm.
(1.124 to 1.123 inch). Select parts to insure that the clearance between
each piston and mating cylinder is within 0.08 to 0.13 mm. (0.003 to
0.005 inch). Use unused SBR cups. To remove dirt and debris, rinse the
cups in 90 percent ethyl alcohol for not more
[[Page 353]]
than 30 seconds and wipe dry with a clean lint-free cloth. Discard any
cups showing defects such as cuts, molding flaws, or blisters. Measure
the lip and base diameters of all cups with an optical comparator or
micrometer to the nearest 0.02 mm. (0.001 inch) along the centerline of
the SAE and rubber-type identifications and at right angles to this
centerline. Determine base diameter measurements at least 0.4 mm. (0.015
inch) above the bottom edge and parallel to the base of the cup. Discard
any cup if the two measured lip or base diameters differ by more than
0.08 mm. (0.003 inch). Average the lip and base diameters of each cup.
Determine the hardness of all cups according to S7.4. Dip the rubber and
metal parts of wheel cylinders, except housing and rubber boots, in the
fluid to be tested and install them in accordance with the
manufacturer's instructions. Manually stroke the cylinders to insure
that they operate easily. Install cylinders in the simulated brake
system.
(b) Master cylinder assembly. Use an unused master cylinder and
unused standard SBR primary and secondary MC cups which have been
inspected, measured and cleaned in the manner specified in S6.13.4(a),
omitting hardness of the secondary MC cup. However, prior to determining
the lip and base diameters of the secondary cup, dip the cup in test
brake fluid, assemble on the MC piston, and maintain the assembly in a
vertical position at 23 deg.5 deg.C.
(73.4 deg.9 deg.F.) for at least 12 hours. Inspect the
relief and supply ports of the master cylinder; discard the cylinder if
ports have burrs or wire edges. Measure the internal diameter of the
cylinder at two locations (approximately midway between the relief and
supply ports and approximately 19 mm. (0.75 inch) beyond the relief port
toward the bottom or discharge end of the bore), taking measurements at
each location on the vertical and horizontal centerline of the bore.
Discard the cylinder if any reading exceeds the maximum or minimum
limits of 28.65 to 28.57 mm. (1.128 to 1.125 inch). Measure the outside
diameter of each end of the master cylinder piston at two points
approximately 90 deg. apart. Discard the piston if any of these four
readings exceed the maximum or minimum limits of 28.55 to 28.52 mm.
(1.124 to 1.123 inch). Dip the rubber and metal parts of the master
cylinder, except the housing and push rod-boot assembly, in the brake
fluid and install in accordance with manufacturer's instructions.
Manually stroke the master cylinder to insure that it operates easily.
Install the master cylinder in the simulated brake system.
(c) Assembly and adjustment of test apparatus.
(1) When using a shoe and drum type apparatus, adjust the brake shoe
toe clearances to 1.00.1 mm (0.0400.004 inch).
Fill the system with brake fluid, bleeding all wheel cylinders and the
pressure gage to remove entrapped air. Operate the actuator manually to
apply a pressure greater than the required operating pressure and
inspect the system for leaks. Adjust the actuator and/or pressure relief
valve to obtain a pressure of 6895 kPa345 kPa
(1,00050 p.s.i.). A smooth pressure stroke pattern is
required when using a shoe and drum type apparatus. The pressure is
relatively low during the first part of the stroke and then builds up
smoothly to the maximum stroking pressure at the end of the stroke, to
permit the primary cup to pass the compensating hole at a relatively low
pressure. Using stroking fixtures, adjust the actuator and/or pressure
relief valve to obtain a pressure of 6895 kPa345 kPa
(1,00050 p.s.i.).
(2) Adjust the stroking rate to 1,000100 strokes per
hour. Record the fluid level in the master cylinder standpipe.
S6.13.5 Procedure. Operate the system for 16,0001,000
cycles at 23 deg.5 deg.C. (73.4 deg.9 deg.F.).
Repair any leakage, readjust the brake shoe clearances, and add fluid to
the master cylinder standpipe to bring to the level originally recorded,
if necessary. Start the test again and raise the temperature of the
cabinet within 62 hours to 120 deg.5 deg.C.
(248 deg.9 deg.F.). During the test observe operation of
wheel cylinders for improper functioning and record the amount of fluid
required to replenish any loss, at intervals of 24,000 strokes. Stop the
test at the end of 85,000 total recorded strokes. These totals shall
include the number of strokes during operation at 23 deg.5
deg.C. (73.4 deg.9 deg.F.) and the number of
[[Page 354]]
strokes required to bring the system to the operating temperature. Allow
equipment to cool to room temperature. Examine the wheel cylinders for
leakage. Stroke the assembly an additional 100 strokes, examine wheel
cylinders for leakage and record volume loss of fluid. Within 16 hours
after stopping the test, remove the master and wheel cylinders from the
system, retaining the fluid in the cylinders by immediately capping or
plugging the ports. Disassemble the cylinders, collecting the fluid from
the master cylinder and wheel cylinders in a glass jar. When collecting
the stroked fluid, remove all residue which has deposited on rubber and
metal internal parts by rinsing and agitating such parts in the stroked
fluid and using a soft brush to assure that all loose adhering sediment
is collected. Clean SBR cups in ethanol (isopropanol when testing DOT 5
fluids) and dry. Inspect the cups for stickiness, scuffing, blistering,
cracking, chipping, and change in shape from original appearance. Within
1 hour after disassembly, measure the lip and base diameters of each
cylinder cup by the procedures specified in S6.13.4 (a) and (b) with the
exception that lip or base diameters of cups may now differ by more than
0.08 mm. (0.003 inch). Determine the hardness of each cup according to
S7.4. Note any sludge or gel present in the test fluid. Within 1 hour
after draining the cylinders, agitate the fluid in a glass jar to
suspend and uniformly disperse sediment and transfer a 100 ml. portion
of this fluid to a centrifuge tube and determine percent sediment as
described in S7.5. Allow the tube and fluid to stand for 24 hours,
recentrifuge and record any additional sediment recovered. Inspect
cylinder parts, note any gumming or any pitting on pistons and cylinder
walls. Disregard staining or discoloration. Rub any deposits adhering to
cylinder walls with a clean soft cloth wetted with ethanol (isopropanol
when testing DOT 5 fluids) to determine abrasiveness and removability.
Clean cylinder parts in ethanol (isopropanol when testing DOT 5 fluids)
and dry. Measure and record diameters of pistons and cylinders according
to S6.13.4(a) and (b). Repeat the test if mechanical failure occurs that
may affect the evaluation of the brake fluid.
S6.13.6 Calculation. (a) Calculate the changes in diameters of
cylinders and pistons (see S5.1.13(b)).
(b) Calculate the average decrease in hardness of the seven cups
tested, as well as the individual values (see S5.1.13(c)).
(c) Calculate the increases in base diameters of the eight cups (see
S5.1.13(e)).
(d) Calculate the lip diameter interference set for each of the
eight cups by the following formula and average the eight values (see
S5.1.13(f)).
[(D1-D2)/(D1-
D3)]x100=percentage Lip Diameter Interference Set
where:
D1=Original lip diameter.
D2=Final lip diameter.
D3=Original cylinder bore diameter.
S6.14 Container information. Each container with information marked
directly on the container surface or on a label (labels) affixed to the
container pursuant to S5.2.2.2 or S5.2.2.3 is subjected to the following
procedure:
(a) If the container has a label affixed to it, make a single
vertical cut all the way through the label with the container in the
vertical position.
(b) Immerse the container in the same brake fluid or hydraulic
system mineral oil contained therein for 15 minutes at room temperature
(235 deg.C; 73.49 deg.F).
(c) Within 5 minutes after removing the container from the fluid or
oil, remove excess liquid from the surface of the container by wiping
with a clean dry cloth.
S7. Auxiliary test methods and reagent standards.
S7.1 Distilled water. Nonreferee reagent water as specified in ASTM
D1193-70, ``Standard Specifications for Reagent Water,'' or water of
equal purity.
S7.2 Water content of motor vehicle brake fluids. Use analytical
methods based on ASTM D1123-59, ``Standard Method of Test for Water in
Concentrated Engine Antifreezes by the Iodine Reagent Method,'' for
determining the water content of brake fluids, or other methods of
analysis yielding comparable results. To be acceptable
[[Page 355]]
for use, such other method must measure the weight of water added to
samples of the SAE RM-66-04 and TEGME Compatibility Fluids within
15 percent of the water added for additions up to 0.8
percent by weight, and within 5 percent of the water added
for additions greater than 0.8 percent by weight. The SAE RM-66-04
Compatibility Fluid used to prepare the samples must have an original
ERBP of not less than 205 deg.C (401 deg.F) when tested in accordance
with S6.1. The SAE TEGME fluid used to prepare the samples must have an
original ERBP of not less than 240 deg.C (464 deg.F) when tested in
accordance with S6.1.
S7.3 Ethanol. 95 percent (190 proof) ethyl alcohol, USP or ACS, or
Formula 3-A Specially Denatured Alcohol of the same concentration (as
specified at 27 CFR 21.35). For pretest washings of equipment, use
approximately 90 percent ethyl alcohol, obtained by adding 5 parts of
distilled water to 95 parts of ethanol.
S7.4 Measuring the hardness of SBR brake cups. Hardness
measurements on SBR wheel cylinder cups and master cylinder primary cups
shall be made by using the following apparatus and the following
procedure.
S7.4.1 Apparatus.
(a) Anvil. A rubber anvil having a flat circular top 201
mm. (\13/16\\1/16\ inch) in diameter, a thickness of at
least 9 mm. (\3/8\ inch) and a hardness within 5 IRHDs of the SBR test
cup.
(b) Hardness tester. A hardness tester meeting the requirements for
the standard instrument as described in ASTM D1415-68, ``Standard Method
of Test for International Hardness of Vulcanized Natural and Synthetic
Rubbers,'' and graduated directly in IRHD units.
S7.4.2 Procedure. Make hardness measurements at
23 deg.2 deg.C. (73.4 deg.4 deg.F.).
Equilibrate the tester and anvils at this temperature prior to use.
Center brake cups lip side down on an anvil of appropriate hardness.
Following the manufacturer's operating instructions for the hardness
tester, make one measurement at each of four points 6 mm from the center
of the cup and spaced 90 deg. apart. Average the four values, and round
off to the nearest IRHD.
S7.5 Sediment by centrifuging. The amount of sediment in the test
fluid shall be determined by the following procedure.
S7.5.1 Apparatus.
(a) Centrifuge tube. Cone-shaped centrifuge tubes conforming to the
dimensions given in Figure 6, and made of thoroughly annealed glass. The
graduations shall be numbered as shown in Figure 6, and shall be clear
and distinct. Scale-error tolerances and smallest graduations between
various calibration marks are given in Table V and apply to calibrations
made with air-free water at 20 deg.C. (68 deg.F.).
[GRAPHIC] [TIFF OMITTED] TC01AU91.048
Fig. 6. ASTM 8-in. Centrifuge Tube
Table V--Calibration Tolerances for 8-Inch Centrifuge Tube
------------------------------------------------------------------------
Volume
Range, ml Subdivision, tolerance,
ml ml
------------------------------------------------------------------------
0 to 0.1...................................... 0.05 a r.p.m. at 700
600 r.c.f r.c.f.
------------------------------------------------------------------------
483............................................... 1490 1610
508............................................... 1450 1570
533............................................... 1420 1530
559............................................... 1390 1500
------------------------------------------------------------------------
a Measured in millimeters between tips of opposite tubes when in
rotating position.
S7.5.2 Procedure. Balance the corked centrifuge tubes with their
respective trunnion cups in pairs by weight on a scale, according to the
centrifuge manufacturer's instructions, and place them on opposite sides
of the centrifuge head. Use a dummy assembly when one sample is tested.
Then whirl them for 10 minutes, at a rate sufficient to produce a r.c.f.
between 600 and 700 at the tips of the whirling tubes. Repeat until the
volume of sediment in each tube remains constant for three consecutive
readings.
S7.5.3 Calculation. Read the volume of the solid sediment at the
bottom of the centrifuge tube and report the percent sediment by volume.
Where replicate determinations are specified, report the average value.
S7.6 Standard styrene-butadiene rubber (SBR) brake cups. SBR brake
cups for testing motor vehicle brake fluids shall be manufactured using
the following formulation:
Formulation of Rubber Compound
------------------------------------------------------------------------
Parts by
Ingredient weight
------------------------------------------------------------------------
SBR type 1503a.............................................. 100
Oil furnace black (NBS 378)................................. 40
Zinc oxide (NBS 370)........................................ 5
Sulfur (NBS 371)............................................ 0.25
Stearic Acid (NBS 372)...................................... 1
n-tertiary butyl-2-benzothiazole sulfenamide (NBS 384)...... 1
Symmetrical dibetanaphthyl-p-phenylenediamine............... 1.5
Dicumyl peroxide (40 percent on precipitated CaCO3)b........ 4.5
-----------
Total................................................. 153.25
------------------------------------------------------------------------
a Philprene 1503 has been found suitable.
b Use only within 90 days of manufacture and store at temperature below
27 deg.C. (80 deg.F.).
Note: The ingredients labeled (NBS) must have properties identical with
those supplied by the National Bureau of Standards.
Compounding, vulcanization, physical properties, size of the finished
cups, and other details shall be as specified in appendix B of SAE
J1703b. The cups shall be used in testing brake fluids either within 6
months from date of manufacture when stored at room temperature below 30
deg.C. (86 deg.F.) or within 36 months from date of manufacture when
stored at temperatures below minus 15 deg.C. (+5 deg.F.). After
removal of cups from refrigeration they shall be conditioned base down
on a flat surface for at least 12 hours at room temperature in order to
allow cups to reach their true configuration before measurement.
S7.7 Isopropanol. ACS or reagent grade.
[36 FR 22902, Dec. 2, 1971]
Editorial Note: For Federal Register citations affecting
Sec. 571.116, see the List of Sections Affected, which appears in the
Finding Aids section of the printed volume and on GPO Access.