TRAILER BRAKES INFORMATION

TRAILER BRAKES

VEHICLES AFFECTED: ALL LIGHT DUTY TRUCK MODELS ----------------- Trailer brakes of adequate size are required on trailers over 450 Kg (1,000 lbs.) loaded weight. Follow the instructions of the manufacturer for proper installation and balance.

Typically, trailer brake installations require less than 0.3 cubic centimeters (0.02 cubic inches) of fluid from the master cylinder to operate. Systems requiring more than 0.3 cubic centimeters of fluid must not be installed because the truck brake fluid capacity will NOT be sufficient to operate the truck and trailer brakes under every condition.

The brake fluid tap on light duty trucks including the 1988 C/K models equipped with rear wheel anti-lock (RWAL) brakes, must be made to the master cylinder port supplying fluid to rear brakes before the combination valve. On the 1988 C/K, this installation will allow the truck to continue operating with RWAL brakes while the trailer brakes operate independently of the RWAL brake system.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.