[Federal Register Volume 59, Number 212 (Thursday, November 3, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-27261]
[[Page Unknown]]
[Federal Register: November 3, 1994]
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DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
Federal Motor Vehicle Safety Standards; Brake Hoses and Motor
Vehicle Brake Fluids; Termination of Rulemaking
AGENCY: National Highway Traffic Safety Administration (NHTSA), DOT.
ACTION: Termination of rulemaking.
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SUMMARY: This document terminates a rulemaking proceeding that
commenced in March 1985 when NHTSA granted a petition for rulemaking
from the United States Army Tank-Automotive Command. The petition
requested that NHTSA amend Standard No. 106, Brake Hoses, to require
brake hose compatibility with a brake fluid with DOT 5 characteristics,
and amend Standard No. 116, Motor Vehicle Brake Fluids, to require
compatibility of DOT 3, DOT 4, and DOT 5 test fluids with elastomeric
seals and cups in hydraulic brake system master and wheel cylinders.
After receiving further information from the petitioner and after
reviewing its own data base, NHTSA has concluded there is no safety
need to amend the standards.
FOR FURTHER INFORMATION CONTACT: Mr. Chris Tinto, Office of Vehicle
Safety Standards, National Highway Traffic Safety Administration, 400
Seventh Street SW., Washington, D.C. 20590. Mr. Tinto's telephone
number is (202) 366-5229.
SUPPLEMENTARY INFORMATION:
Background and Grant of Petition
On March 20, 1985, NHTSA published a Federal Register document (50
FR 11213) granting a petition for rulemaking submitted by the United
States Army Tank-Automotive Command (ATAC), to amend Federal Motor
Vehicle Safety Standards Nos. 106, Brake Hoses, and 116, Motor Vehicle
Brake Fluids. The petitioner requested NHTSA to expand the number and
type of ``referee materials'' used to test samples of brake hose
(Standard No. 106) and brake fluid (Standard No. 116) for compliance
with the requirements of those standards.
Referee materials are used in the test procedures of Standards Nos.
106 and 116 to represent typical fluids and components that are present
in real-world brake systems. The referee materials are combined with
the test sample of brake hose or fluid to determine the compatibility
of the referee material and the test sample. At the time the petition
was filed, Standard No. 106 referenced a referee material called RM-1
SAE Compatibility Fluid to test hydraulic brake hose and hose
assemblies.1 Standard No. 116 also referenced RM-1 SAE
Compatibility Fluid to test samples of DOT 3, DOT 4, and DOT 5 brake
fluid. In addition, Standard No. 116 referenced another referee
material, ``SAE referee cups'' made of styrene butadiene rubber (SBR),
to test the compatibility of test samples of DOT 3, DOT 4, and DOT 5
brake fluid with the material. In all cases involving the use of
referee materials, the referee materials are combined with the test
sample of hose or fluid to see the effect of the combination. For
example, in Standard No. 116's test evaluating the effect of brake
fluid on cups (S5.1.12), the referee SBR cups are immersed in the test
fluid, heated, then examined for disintegration, hardness changes and
diametrical changes.
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\1\In 1986, Standards No. 106 and 116 were amended to replace
RM-1 SAE compatibility fluid with RM-66-03 fluid. (See 51 FR 16694.)
In October 1992, NHTSA published a notice of proposed rulemaking to
update the referee fluid to RM-66-04, effective January 1, 1995, as
RM-66-03 is no longer readily available. (See 57 FR 49162.)
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ATAC requested that Standard Nos. 106 and 116 be amended in two
primary ways. First, the petitioner suggested that Standard No. 106 be
amended to require brake hose compatibility with a fluid with DOT 5
(silicone) brake fluid characteristics. ATAC stated that the U.S. Army
adopted DOT 5 silicone brake fluid as its standard operating fluid for
its motor vehicles with hydraulic brake systems. After replacing the
brake fluid with DOT 5 fluid in some of its vehicles, the Army had
operational problems with aftermarket procured hydraulic brake system
components. The Army believed it had traced the problem to excessive
swelling of elastomeric seals and cups within the hydraulic brake
system master cylinder. The swelling appeared to be caused by
incompatibility problems between the DOT 5 brake fluid and brake system
components made of rubber. Since Standard No. 106 does not test brake
hose and hose assemblies with a referee material brake fluid
representing DOT 5 (silicone) fluid, ATAC suggested amending Standard
No. 106 to require brake hose compatibility with a silicone fluid.
Second, ATAC suggested that Standard No. 116 be amended to require
that master and wheel cylinder cups made of ethylene propylene diene
monomer rubber (EPDM) be compatible with a DOT 3, DOT 4 and DOT 5 brake
fluid referee material, and to include specifications for these EPDM
and other rubber components. The tests in Standard No. 116 that measure
the effect of brake fluid with rubber are run with SAE referee material
SBR cups only. ATAC believed that the aftermarket EPDM brake system
components it encountered were incompatible with the DOT 5 brake fluid
in its vehicles.
The agency believed that the issues raised by ATAC warranted
further consideration. Thus, NHTSA granted ATAC's petition.
Rationale for Termination
Subsequent to its petition, ATAC provided further information to
NHTSA indicating that its problem had been resolved. Tests conducted by
the Army at Fort Belvoir, Virginia, implied that there was some
confusion as to what actually caused the problem in the braking systems
of the vehicles in question. Nevertheless, ATAC informed NHTSA that it
solved its problem by using only military specification (MIL spec)
brake components and brake fluid in ATAC vehicles. ATAC indicated that
EPDM and SBR components that met the Army's MIL-C-14055, ``Cup,
Hydraulic Brake Actuating Cylinder, Synthetic Rubber'' specification
perform satisfactorily with silicone brake fluid. ATAC further
indicated that if MIL spec MIL-C-14055 were used for parts procurement,
it would avoid any problems of component deterioration in the future.
NHTSA supplemented this information with data for non-military
motor vehicles. NHTSA believed that if brake fluid compatibility
problems similar to those experienced by ATAC were occurring in non-
military vehicles, the public would have reported some of these
incidents to NHTSA's Auto Safety Hotline. The Hotline is a
comprehensive database that encompasses over 250,000 consumer calls,
dating back to 1981, relating to vehicle and component performance and
complaints. Approximately 35,000 of these calls are about brake-related
performance. NHTSA conducted a database search for all complaints
relating to brake fluid in passenger cars, light trucks, buses and
heavy trucks, and found no evidence of a safety problem. The agency
found only 17 complaints that referred to ``brake fluid'' as the basis
for the complaint. The majority of the complaints referred to
contamination problems (water, fuel, and other fluid intrusion into the
brake fluid).
Moreover, approximately 8 of the 17 complaints concerned vehicles
that had traveled fewer than 50,000 miles. Because of their relatively
low mileage, NHTSA does not believe these vehicles had anything other
than the original brake fluid in them. Given the preponderance of
vehicles manufactured with DOT 3 fluid over vehicles manufactured with
DOT 5 fluid, the agency believes the original brake fluid in the
vehicles in question was DOT 3 fluid, not DOT 5 fluid. There was one
complaint referring to a problem with ``silicone'' brake fluid and
brake system components, involving an antique Jaguar car and a certain
brand of silicone fluid. A single complaint in a database as
encompassing as the Hotline complaint file does not indicate the
possible existence of a significant safety problem.
In conclusion, there is no evidence of a safety problem regarding
the compatibility of silicone fluid and brake system components. NHTSA
believes that if there were a safety problem with brake fluid and
component compatibility, evidence of the problem would have appeared in
the ten years since ATAC's petition was received by NHTSA. No such
evidence has manifested. Accordingly, the agency is terminating this
rulemaking action.
Authority: 49 U.S.C. 322, 30111, 30115, 30117 and 30166;
delegation of authority at 49 CFR 1.50.
Issued on: October 27, 1994.
Barry Felrice,
Associate Administrator for Rulemaking.
[FR Doc. 94-27261 Filed 11-2-94; 8:45 am]
BILLING CODE 4910-59-P
