Interpretation ID: nht81-2.37

DATE: 06/19/81

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Tokai Rubber Industries, Ltd.

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your recent letter regarding several new kinds of plastic vacuum brake hoses that you plan to manufacture. The plastic brake hoses are flexible nylon tubes for use in a vacuum braking system. You indicate that these hoses cannot comply with several provisions of Safety Standard No. 106, and ask whether the plastic hoses could qualify as "vacuum tubing connectors."

Safety Standard No. 106 (49 CFR 571.106) specifies performance and labeling requirements for brake hose, which is defined in the standard 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."

Since the nylon tubes which you plan to manufacture will transmit the vacuum used to apply force to a vehicle's brakes, the tubes would qualify as "brake hose" under this definition and would be subject to all requirements of Safety Standard No. 106. Moreover, it appears that the nylon tubes would not qualify as "vacuum tubing connectors," which are excepted from compliance with the standard in the definition of brake hose. Section 4 of Safety Standard No. 106 defines "vacuum tubing connector" as:

"a flexible conduit of vacuum that (i) connects metal tubing to metal tubing in a brake system, (ii) is attached without end fittings, and (iii) when installed, has an unsupported length less than the total length of those portions that cover the metal tubing."

According to the illustrated drawings included in your letter, the nylon flexible tubes with which you are concerned would have an unsupported length which is greater than the total length of those portions that cover metal tubing. Therefore, the nylon tubes would not qualify as "vacuum tubing connectors" under subsection (iii) of the above definition. The purpose of the definition is to except from compliance with the standard only those vacuum connectors that have unsupported lengths short enough that they will not sag or deflect because of their own weight. While your nylon tubes may be sturdy enough to meet this intended purpose, as the definition is currently written, the tubes cannot be considered vacuum tubing connectors.

If, as your letter indicates, the nylon brake hose does not comply with all requirements of Safety Standard No. 106, you would not be permitted to sell it in the United States. You may wish to petition the agency to amend Standard No. 106 to establish separate performance requirements specifically designed for nylon vacuum tubing such as that produced by Tokai. I am enclosing a copy of the procedures which explain how you can file a petition, in case you are interested.

Sincerely,