Interpretation ID: nht73-1.9

DATE: 10/29/73

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

TO: T. N. O'Leary, Esq.

TITLE: FMVSS INTERPRETATION

TEXT: In your letter of October 8, 1973, to the Department of Transportation you ask whether it is true that DOT requires trailer braking systems to have stainless steel conduits rather than copper ones.

Neither the Federal motor vehicle safety standards nor the regulations of the Bureau of Motor Carrier Safety contain such a requirement, and we are unaware of any Federal regulation of this nature.

Yours truly,

October 8, 1973

Office of the General Counsel -- Department of Transportation

Gentlemen:

We have been informed that there is a Department of Transportation regulation to the effect that trailers hauled behind motor vehicles must have stainless steel, as opposed to copper conduits for their gravitational braking systems. As I understand it, the idea behind the gravitational braking system is that when the car puts on its brakes, the trailer naturally exerts forward pressure on the hitch, and this pressure in turn activates the conduits or braking system in such a way that brake fluid flows through the conduit and puts the brakes on the crailer in action.

If there is, in fact, such a regulation, I would appreciate your pointing it out to me. Thank you.

Yours very truly,

PAIN & JULIAN --

Thomas N. O'Leary

P.S. Also, I would appreciate knowing the reasons behind such a regulation and the evidentiary effect, if any, in a Court of Law for such a rule.