Interpretation ID: nht74-2.25

DATE: 05/10/74

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

TO: Kelsey-Hayes Company

TITLE: FMVSS INTERPRETATION

TEXT: This will acknowledge receipt of Kelsey-Hayes' petition to add "after-stop" to the description of temperature range in S6.1.8.1 of Standard No. 121 and S7.4.2.1.2 of Standard No. 105a.

The temperature range is in fact intended to describe the after stop temperature of the brakes, and the language of the sections will be clarified in the future.

Yours truly,

ATTACH.

April 25, 1974

U. S. Department of Transportation, National Highway Traffic Safety Administration,

Richard B. Dyson -- Assistant Chief Counsel

RE: Requests for Interpretation -- FMVSS 105 (9/1/75) S7.4.2.1.2; FMVSS 121 S6.1.8.1; Your file numbers N40-30 (ZTV) and (TWH); Brake Burnish Procedure

Dear Mr. Dyson:

You have responded to our requests for interpretation on identical language in these subsections of these standards and advised that the word maximum would be deleted in the sentence ending in ". . . maintain a maximum temperature of 500 degrees F +/- 50 degrees F."

We recommend one further clarification to eliminate ambiguity, namely, that the phrase "after-stop temperature" be added to the sentence, as follows:

"If during any of the brake applications specified in , the hottest brake reaches 500 degrees F, make the remainder of the 500 applications from that speed except that a higher or lower speed shall be used as necessary to maintain an after-stop temperature of 500 degrees F +/- 50 degrees F."

We further suggest that a notice be issued proposing this clarification.

Very truly yours,

John F. McCuen -- Attorney, KELSEY-HAYES COMPANY

cc: W. T. Birge; D. Renner