THIS BULLETIN CANCELS TRUCK SERVICE BULLETIN 86-T-183. ALL COPIES OF 86-T-183 SHOULD BE DESTROYED; THEY CONTAIN AN INCORRECT PART NUMBER.
In the event the brake master cylinder cover does not appear to be sealing properly, the cover should be inspected for the following:
- Bowed or deformed edges on the reservoir cover.
- Cracked reservoir cover.
- Unsnapped reservoir cover.
1. If any of these conditions are noted, the reservoir cover and diaphragm assembly should be removed and discarded.
2. Refill the reservoir with brake fluid, Delco Supreme II DOT-3, P/N 1052535, or equivalent
3. Install kit, P/N 18014184, which includes a new cover and diaphragm assembly.
- Inspect diaphragm to assure that is is completely seated in cover.
- Make sure the cover and diaphragm assembly is fimly snapped to the reservoir.
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.