This is a partial copy of the publicatio. If you want to see the whole thing goto: www.access.gpo.gov/nara/cfr/cfr-table-search.html and follow the index to Title 49, Part 571, Sec. 571.116, Standard no.1 116 (motor vehicle brake fluids)
[Code of Federal Regulations]
[Title 49, Volume 5, Parts 400 to 999]
[Revised as of October 1, 1998]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR571.116]
[Page 339-364]
TITLE 49--TRANSPORTATION
CHAPTER V--NATIONAL HIGHWAY TRAFFIC
SAFETY ADMINISTRATION, DEPARTMENT
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.
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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
500<SUP>plus-minus</SUP>10 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.).
(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 (13<SUP>plus-minus</SUP>1 mm. (\1/
2\<SUP>plus-minus</SUP>\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 23<SUP>plus-minus</SUP>5 deg. C
(73.4<SUP>plus-minus</SUP>9 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;
[[Page 341]]
(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 40<SUP>plus-minus</SUP>2 deg. C. (minus 40<SUP>plus-</SUP> 144<SUP>plus-mi</SUP> 10
<SUP>minus</SUP>3.6 deg. F.).............................. <SUP>n</SUP>4.0
Minus 50<SUP>plus-minus</SUP>2 deg. C. (minus 58<SUP>plus-</SUP> 6<SUP>plus-minu</SUP> 35
<SUP>minus</SUP>3.6 deg. F.).............................. <SUP>s</SUP>0.2
------------------------------------------------------------------------
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 <SUP> deg.</SUP>C. (140 <SUP> deg.</SUP><greek-PH><SUP>.).</SUP>
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(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;
[[Page 342]]
(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: