ACCESSORY BELT NOISE (INSTALL AIR PUMP BRACKET)

VEHICLES AFFECTED: 1988 CORVETTES EQUIPPED WITH MANUAL TRANSMISSION WITHOUT B2K (CALLOWAY PACKAGE)

Some 1988 Corvettes equipped with manual transmission may experience a noise resulting from slippage between the accessory drive belt and the water pump pulley.

The noise is most noticeable when the car is being accelerated briskly with the A/C off and the transmission shifts from non-overdrive to the overdrive mode.

This condition may be addressed by the removal of the water pump damper and installation of a brace, P/N 10105234, under the air pump. When removing the water pump damper, it is necessary to remove the water pump pulley studs and reattach the water pump pulley by using 4 bolts, P/N 14067335.

Parts Required

1 P/N 10105234 Brace 4 P/N 14067335 Bolts 1 P/N 10105235 Screw

Service Procedure

1. Loosen the air pump pulley bolts and the water pump damper nuts.

2. Remove the accessory drive belt by rotating the tensioner clock-wise and. lifting the belt over the alternator pulley.

3. Remove the water pump damper and water pump pulley.

4. Remove the 4 studs in the water pump flange and reinstall the pulley with 4 bolts, P/N 14067335. Torque to 20-27 Nm.

5. Remove the air pump pulley from the pump.

6. Remove the lower air pump attaching bolt (See Illustration).

7. Remove the inboard nut that retains the air pump bracket to the engine per Illustration.

8. Install brace, P/N 10105234, over the stud at the inboard mounting of the air pump bracket and install a new lower air pump attaching screw, P/N 10105235 through the other end of the brace and through the bracket and pump at the lower attaching point per Illustration. Tighten the bracket/brace attaching nut to 26-40 Nm. Tighten the new lower air pump attaching bolt to 40-60 Nm.

9. Re-install the air pump pulley and torque the attaching bolts to 22-30 Nm.

10. Re-install the accessory drive belt and start the engine to ensure that the belt is properly seated.

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.