Interpretation ID: aiam1868
Unique Truck Accessories
10343 East Rush
South El Monte
CA 91733;
Dear Mr. Sousamian: This responds to your March 14, 1975, request for confirmation that mechanical parking brake device may be installed on air-braked trailers that were manufactured prior to January 1, 1975. We did not receive the literature you intended to enclose with your letter.; Standard No. 121 applies only to trailers manufactured after January 1 1975, and trucks and buses manufactured after March 1, 1975. The standard does not therefore, prevent the installation of a mechanical parking brake on trailers manufactured before January 1, 1975.; As for trailers manufactured in compliance with Standard No. 21, th standard does not prohibit the installation of a mechanical parking brake at the time of manufacture as long as the installation does not interfere with vehicle conformity. The mechancial (sic) device could also be installed after the first purchase of the trailer in good faith for purposes other than resale (i.e., the retail sale), as long as it does not involve the knowing disconnection of the 121-system by a manufacturer, distributor, dealer, or repair business.; Although you are no doubt aware of relevant Bureau of Motor Carrie Safety regulations, I have enclosed a copy of them for your information.; Yours truly, Richard B. Dyson, Assistant Chief Counsel