SERVICE MANUAL UPDATE SEC.8A CONV. ROOF MANUAL BYPASS VALVE

VEHICLES AFFECTED: 87-90 PONT AND 87-90-CHEV J

The manual bypass valve shown on the circuit diagram on page 8A-121-0 is not used. Please insert the attached Hydraulic diagram over the existing hydraulic diagram on page 8A-121-0.

On page 8A-121-1, under TROUBLE SHOOTING HINT 3, the sentence "Manual Bypass Valve near Hydraulic Power Assembly is closed (turned fully clockwise)." should be deleted since it does not apply.

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.