Interpretation ID: nht74-3.29

DATE: 09/17/74

FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA

TO: The Weatherland Company

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of August 14, 1974, pointing out a discrepancy in the constriction test requirements for hydraulic brake hose found in Federal Motor Vehicle Safety Standard No. 106-74.

We are considering a change in our next notice concerning Standard 106-74, so that S6.7.2(c) will conform with S5.3.1 as that paragraph was amended by Notice 11 (39 F.R. 24012).

Yours Truly,

The Weatherhead Company

August 15, 1974

Reference: MUE 486

Richard B. Dyson Assistant Chief Counsel -- NHTSA

Subject: FMVSS 571.106-74 Reference Notice 11 Docket 1-5

Your timely personal response to our request for clarification of the labeling of 1/8 inch O.D. SAE J844c nylon air brake tubing is sincerely appreciated. The NHTSA's determination to exempt this small sized tubing is reasonable, without adverse effect on vehicle safety, and sustains the usage of an economic product.

While preparing our corporate documentation to support product compliance with 571.106-74 a troublesome inconsistency was noted. Perhaps NHTSA can incorporate a minor change in the wording of Para. S6.7.2(c) in the next publication released concerning The Brake Hose Standard.

Paragraph S6.7.2(c) retains the Constriction Test requirement for the complete brake hose assembly stating: "Drain the brake hose assembly, immediately determine that every inside diameter of any section of the hose assembly is not less than 64% of the nominal inside diameter of the hose, and conduct the test specified in S6.2."

As you may recall Notice 11 excluded end fittings, distribution blocks and residual valves by amending constriction requirements to be applicable to only ". . . that part of the fitting in which hose is inserted".

Realizing this inconsistency in Para. S6.7.2(c) is an oversight and that it would not cause an unnecessary compliance variance, a repetitive petition is withheld pending correction.

Thank you once again for responding so promptly to our requests for clarification concerning this Standard.

John H.Mueller

Manager, Engineering Standards

cc: D. Delve

W. Redler