Interpretation ID: nht95-3.58

TYPE: INTERPRETATION-NHTSA

DATE: July 25, 1995

FROM: Robert R. Brester -- Director of Product Engineering, Velvac, Inc.

TO: Steve Wood -- Office of Chief Council, NHTSA

TITLE: NONE

ATTACHMT: ATTACHED TO 10/17/95 LETTER FROM JOHN WOMACK TO ROBERT R. BRESTER (A43; STD. 105; STD. 106)

TEXT: Dear Mr. Wood

On the advice of Mr. Richard Carter with NHTSA, (1-202-366-5274) I am sending you this letter requesting your departments legal interpretation of 571.105 in regards to auxilary braking systems on motor vehicles.

Velvac Inc. manufactures and sells brake components and power braking systems for trailers and truck tag axles. These brake systems are not part of the primary vehicle braking system. In the case of a tag axle, our customers are retrofitting a standard vehicle with an additional axle to increase its load carrying capacity. In the case of a trailer, our system may be the only source of braking.

The brake components Velvac supplies generally include control valving, brake boosters and various types of hoses and fittings. These items can be sold both as components and as complete power brake kits. (See attached a catalogue drawings 003119, 0031 18, 003117 and 003115 to 003128). We do not supply the braking mechanism at the wheels. (brake linings, wheel cylinders etc.) These items come as part of the axle package. Customers specify our components based on the braking requirements for the axle , (hydraulic pressure and displacement required)

Recently, I called Mr. Richard Carter asking for his interpretation of 571.105 and how it affects the brake products we sell. Basically, Mr. Carter indicated that 571.105 has little affect on Velvac since it deals mainly with vehicle braking performance . 571.105 is not detailed in how the requirements are met, therefore, it can be assumed different combinations of braking components may be used to achieve the desired braking results. Furthermore, Velvac has no control over how the customer installs o ur brake systems and components on their vehicles.

The opinion given by Mr. Carter is that the responsibility for certifying the vehicle to 571.105 lies in the hands of our customers.

Mr. Carter indicated that your department would make the official reply regarding this matter and would confer with him regarding the technical details.

Your prompt response on this matter would be greatly appreciated.

(Drawings omitted.)