SQUAWK/MOAN NOISE WHEN TCC IS APPLIED-INSTALL ISOLATION KIT

SUBJECT: SQUAWK/MOAN NOISE WHEN TCC APPLIED (INSTALL ISOLATION KIT AND MODIFY COOLER PIPE CLIPS)

VEHICLES AFFECTED: 1991 C AND H MODELS

Some owners of 1991 'C' or 'H' models may experience a squawk/moan noise when TCC is applied. This condition may be caused by a ground out of the transaxle/engine oil cooler pipes at the cooler pipe clips (see Figure 1) where they attach to the lower tie bar. To correct these conditions, it will be necessary to install isolation kit, part number 25606753, and modify the existing cooler pipe clips. The isolation kit consists of two rubber grommets, two flanged sleeves and 2 hexhead sheet metal screws. Use the procedure below to install these parts and modify the cooler pipe clips.

SERVICE PROCEDURE:

1. Raise vehicle to gain access to cooler pipe clips attached to lower tie bar, refer to Figures 1 and 2.

2. Unlatch both clips to release cooler pipes.

3. Remove clip attaching screws and clips.

4. Enlarge the clip screw attaching holes using a 5/8" drill bit.

5. Install rubber grommets in clips with chamfered side down.

6. Install metal sleeves in grommets with flared side down.

7. Reinstall clips to tie bar with screws provided in the kit.

Note: Care must be taken to trap the evaporative emission cannister line between the lower radiator tie bar and the clip in the space provided.

8. Tighten the screws until the metal sleeve has bottomed against the lower tie bar. Maximum torque not to exceed 3.4 N.m (30 in.lbs.)

9. Lower car.

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.