Interpretation ID: nht78-1.13
DATE: 03/23/78
FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA
TO: Nissan Motor Company
TITLE: FMVSS INTERPRETATION
TEXT: We refer to your letters of November 10 and December 2, 1977, to Mr. Joseph J. Levin, requesting an interpretation of Federal Motor Vehicle Safety Standard (FMVSS) No. 106-74 Brake Hoses. You inquired as to its applicability to the two anti-skid system hoses "A" and "B" in the diagram you enclosed.
The anti-skid actuator apparently modulates the pressure to the rear brakes upon command from the computer module. You stated that the failure of the actuator would not prevent the brake system from meeting the requirements of FMVSS No. 105-75.
You also stated that the subject hoses carry mineral oil, and that such hoses might deteriorate if subjected to brake fluid. You further stated that standard hydraulic brake hoses would deteriorate if used with the mineral oil which is used in the power steering system.
In the preamble to Notice 11, Docket 1-5, published June 24, 1974, (39 FR 24012) all power steering type hoses that connected power steering pumps with accumulators were exempted from coverage by the standard. Hoses connecting accumulators with brake power boosters were also exempted if redundant boosters were provided. The National Highway Traffic Safety Administration (NHTSA) has reviewed this latter interpretation and determined that all power steering type hoses should be exempted from FMVSS No. 106-74, until appropriate requirements for such hoses are established.
After consideration of the information and the drawings in your letters, we have concluded that hose assemblies A and B connected to your anti-skid actuator are, in fact, power steering hose assemblies. Consequently those assemblies are exempt from the subject standard until suitable requirements for such assemblies are included therein.
Sincerely,
ATTACH.
November 10, 1977
Joseph J. Levin -- Office of the Chief Counsel, NHTSA
Dear Mr. Levin:
This letter is to ask your interpretation concerning FMVSS 106 - "brake hoses".
Attached is the schematic drawing of the brake system with the hydraulic anti-skid unit. Do hoses A and B in this drawing fall under the category of "brake hose" which is defined in S.4 of FMVSS 106? In other words, should those hoses meet FMVSS 106?
I look forward to hearing your reply to the above.
Very truly yours
NISSAN MOTOR CO., LTD.;
Tokio Iinuma -- Staff, Safety
Enclosure
December 2, 1977
Joseph J. Levin -- Office of the Chief Counsel; NHTSA
Dear Mr. Levin:
I asked for your interpretation with regard to FMVSS 106 - "brake hoses" in my letter of November 10, 1977.
I am afraid that my explanation concerning hoses used in the anti-skid unit was insufficient.
The following is the additional information necessary to make my explanation complete:
1. Even if the failure (ex: mineral oil leakage from hoses, inoperative of actuator or vane pump) occurs in the anti-skid unit, the vehicle is capable of meeting FMVSS 105 - "hydraulic brake systems".
2. Difference of material between hoses used in anti-skid unit (hose A, B and C in attachment) and hoses in ordinary brake system which is in compliance with FMVSS 106.
HOSES IN HOSES IN ORDINARY ANTI-SKID UNIT BRAKE SYSTEM outer rubber CR CR (or CR+NR) middle rubber NR NR inner rubber NBR SBR
(Graphics omitted)
3. Compatibility with mineral oil or brake fluid (DOT 3).
HOSES IN HOSES IN ORDINARY ANTI-SKID UNIT BRAKE SYSTEM mineral possibility of deterior- oil no problem ation of property and swelling at inner rubber brake possibility of fluid deterioration no problem (DOT 3) of property at inner rubber
Thank you for your attention to the above matter. I look forward to hearing your reply to my letter of November 10, 1977.
Very truly yours, NISSAN MOTOR CO., LTD.,
Tokoi Iinuma -- Staff, Safety
Enclosure
cc: Welfred M. Redler (NHTSA Office of crash avoidance)
Brake System with Anti-Skid Unit
(Graphics omitted)
NOTE: Hoses A, B and C does not make contact with brake fluid (DOT 3) because the flows of mineral oil for the power steering unit and brake fluid for brake systems are completely separate.