Interpretation ID: nht74-1.23

DATE: 08/01/74

FROM: R. B. Dyson -- NHTSA

TO: General Motors Corporation, David A. Martin (ASE)

TITLE: FMVSS INTERPRETATION

TEXT:

Dear Mr. Martin:

This responds to General Motors' July 10, 1974, request for interpretation of paragraph S3., Application, of Standard No. 106-74, Brake hoses, relative to brake booster hose. You refer to language in the preamble to Docket No. 1-5; Notice 11, published June 28, 1974 (39 FR 24012), which stated:

The NHTSA has concluded that the difference in requirements for the hydraulic booster system justifies special performance requirements for this application. Until these requirements are developed, hydraulic brake booster hose running from pump to accumulator will be considered to be exempt from the requirements of this standard. Hose running from accumulator to booster will also be exempted if redundant booster is provided.

This language exempts hoses used in certain functions, but not all. Clearly, booster hose running from accumulator to booster without redundant boost would not be exempt. Therefore, your conclusion that Standard No. 106-74 does not apply to any hydraulic brake booster hose, hydraulic brake booster hose end fittings, or hydraulic brake booster hose assemblies is overbroad and for that reason incorrect.

We suggest you describe in another letter the booster applications in General Motors vehicles which are not clearly categorized by the Notice 11 language. We will then be able to tell you whether or not they are subject to the requirements of Standard No. 106-74.

Yours truly,

Richard B. Dyson Acting Chief Counsel

August 5 - RAR,RLL,DPD,JAN LCL,WCC,CRS,GFB

USG 1137

July 10, 1974

Dr. James B. Gregory Administrator National Highway Traffic Safety Administration Nassif Building Washington, DC 20590

Dear Dr. Gregory:

This letter requests an interpretation of paragraph S3., Application of the amended Motor Vehicle Safety Standard 106-74, Brake Hoses (Docket 1-5, Notice 11, published on June 28, 1974) as it relates to hydraulic brake hoses.

The General Motors petition (USG 1087, dated 3/27/74) for the exclusion of hydraulic booster hoses from applicability under MVSS 106 explained that both the low and high pressure hoses associated with the General Motors hydraulically boosted brake power assist units should be excluded from the hydraulic brake hose performance requirements due to their different working environment and construction. Moreover, we explained that the working fluid within these hydraulic booster hoses and the hydraulically boosted brake power assist unit is completely separate from the brake system master cylinder and the hydraulic brake hoses which contain the hydraulic brake fluid used to apply force to the vehicle's brakes.

Notice 11 preamble refers to this General Motors petition requesting exclusion of hydraulic booster hoses from the MVSS 106-74 requirements and concludes:

The NHTSA has concluded that the difference in requirements for the hydraulic booster system justifies special performance requirements for this application. Until these requirements are developed, hydraulic brake booster hose . . . will be considered to be exempt from the requirements of this standard.

This portion of the preamble leads General Motors to conclude that the Administrator's intent was to exempt all hydraulic brake booster lines.

Accordingly, General Motors interpretation of paragraph S3., Application, is that MVSS 106-74 does not apply to hydraulic brake booster hose, hydraulic brake booster hose end fittings, or hydraulic brake booster hose assemblies. A prompt verification of this interpretation is urgently needed, particularly since the amendment itself does not contain any provision stating that MVSS 106-74 is not applicable to hydraulic brake booster hoses, end fittings, and assemblies.

Very truly yours,

David E. Martin, Manager Automotive Safety Engineering

ld