LOOSE WATER PUMP PULLEY (REPLACE WATER PUMP)

SUBJECT: LOOSE WATER PUMP PULLEY

MODELS AFFECTED: 1991-1992 MODELS WITH 4.5L OR 4.9L ENGINE

Some 1991-1992 vehicles equipped with 4.5L or 4.9L engines may experience a loose water pump pulley.

This condition may exhibit itself as a click-type noise. The cause of this condition has been determined to be paint in the threads of the water pump flange which prevents the pulley attaching bolts from fully seating.

When repairing this condition, the water pump flange threads should be inspected to assure that they have not been damaged. Water pump replacement is necessary if thread damage is encountered. If threads appear OK, running a tap through the hole will clean the paint from the threads. If a new water pump is installed, chasing the threads should also be performed as GMSPO service stock may also contain pumps with paint in the threads.

Pulley bolts should be torqued to 35 N.m (25 lbs. ft.). When this torque is applied, the bolt head should be pressed firmly against the pulley.

WARRANTY INFORMATION:

Operation VEHICLE SERIES Operation Description Number C D E J K V --------------------- ----------------------------------- Pump, and/or Gasket, Coolant - Replace J3480 1.7 1.3 1.3 1.0

On jobs which only require retapping the flange use Labor Operation T6609 at .3 hour for all vehicles.

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.