Interpretation ID: 1984-4.12

TYPE: INTERPRETATION-NHTSA

DATE: 12/21/84

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: Rivkin Sherman and Levy -- Donald M. Schwentker

TITLE: FMVSS INTERPRETATION

TEXT:

Donald M. Schwentker, Esq. Rivkin Sherman and Levy 900 17th Street N.W. Washington, D.C. 20006

This responds to your letter concerning the applicability of Federal Motor Vehicle Safety Standard (FMVSS) No. 106, Brake Hoses, to what you referred to as "semi-rigid" brake tubing. In your letter, you stated your belief that the term "flexible conduit" in FMVSS No. 106 excludes semi-rigid tubing of metal or plastic. You requested the National Highway Traffic Safety Administration (NHTSA) to concur in your interpretation that the word " flexible" designates a conduit that is "flexible in operation rather than flexible to facilitate installation on the vehicle." You also asked whether a coupler designed for attachment to the end of such a semi-rigid tube is included in the standard's definition of a brake hose end fitting.

By way of background information, you should be aware that NHTSA does not pass approval on the compliance of any vehicle or equipment with a safety standard before the actual events that underlie certification. Under the Vehicle Safety Act, the manufacturer is required to determine whether its vehicles and equipment comply with all applicable safety standards and regulations, and to certify its products in accordance with that determination.

Federal Motor Vehicle Safety Standard No. 106 defines "brake hose" as:

a flexible conduit, other than a vacuum tubing connector, manufactured for use in a brake system to transmit or contain the fluid pressure or vacuum used to apply force to a vehicle's brakes.

Your first question asked whether the concept of flexibility is limited solely to conduits designed to flex in operation. The answer is no. The agency has included semi-rigid tubing in the definition of brake hose even if such tubing does not bend or flex during normal vehicle operation. In a November 28, 1975 preamble on Standard No. 106 (40 FR 55f65), the agency stated that:

(The functional definition of "brake hose" would be retained. There would thus be no exception for flexible chassis plumbing, even though such tubing is also outside the scope of the traditional conception of brake hose. The NHTSA remains convinced that such tubing, because it invites bending during repairs, should remain within the coverage of the standard.

The agency also explained in a February 26, 1974 preamble (39 FR 7425) that a safety need exists to include flexible chassis plumbing in Standard No. 106, because it is used in the same environment as hose located at articulating points and is subject to the same types of stress. That notice denied petitions requesting that tubing be excluded from the standard.

Under Standard No. 106, therefore, flexible chassis-mounted vacuum brake tubing which transmit or contain the vacuum used to apply force to a vehicle's brakes are included in the definition of brake hose.

Your second question asked whether a coupler designed for attachment to the end of a semi-rigid tube is a "brake hose end fitting." Standard No. 106 defines a brake hose end fitting as "a coupler, other than a clamp, designed for attachment to the end of a brake hose." The answer to your question, therefore, depends on whether a particular conduit is a brake hose. If a coupler attaches to a brake hose, then the coupler is a brake hose end fitting subject to FMVSS No. 106.

Sincerely,

Frank Berndt Chief Counsel

February 15, 1984

Frank A. Berndt, Esquire Chief Counsel National Highway Traffic Safety Administration 400 Seventh Street, S.W. Washington, D.C. 20590

Applicability of FMVSS 106 to Chassis-Mounted Vacuum Brake Tubing

Dear Mr. Berndt:

Brake hose is defined in FMVSS 106 (49 CFR S571.106-74) as "a flexible conduit, other than a vacuum tubing connector, manufactured for use in a brake system to transmit or contain the fluid pressure or vacuum used to apply force to a vehicle's brakes". We interpret the word flexible in the definition to mean a conduit that is flexible in operation rather than flexible to facilitate installation on the vehicle. Typically, metal, plastic or polyamide tubing is used for that portion of the brake line that is attached to the vehicle's chassis. Such tubing usually is non-rigid so as to facilitate installation, but, once installed, does not bend or flex during normal vehicle operation.

Therefore, it is our understanding that the brake hose requirements of FMVSS 106 apply only to conduits that are designed to be flexible in operation -- that is those linking the brake tubing fitted to the chassis to unsprung parts of the suspension system. But for convenience of installation, the tubing attached to the chassis could be absolutely rigid, and therefore clearly outside of the standard's definition of brake hose. The standard was intended to apply to brake hose required to be flexible in operation, and therefore usually made of rubber. For example, the FMVSS 106 whip test and the ozone resistance test have no real applicability to a relatively stiff plastic or polyamide tube. In fact, the primary concern with such tubing is not ozone, but ultra-violet, and no such durability requirement is specified in FMVSS 106.

In summary, we would like your confirmation of our interpretation that the term flexible conduit as used in the definition of brake hose in FMVSS 106 does not include semi-rigid tubing of metal or plastic not designed to flex during normal vehicle operation, nor does the term brake hose end fitting apply to a coupler designed for attachment to the end of such a semi-rigid tube.

A timely response would be appreciated.

Sincerely,

RIVKIN SHERMAN and LEVY

Donald M. Schwentker

DMS:kg