A/C COMPRESSOR MOAN,GROWL,VIB. NEW MOUNTING BRACE/HOSE ASSY.

VEHICLES AFFECTED: 1987-90 'A' W/2.8, 3.1

THIS BULLETIN HAS BEEN REVISED TO CORRECT THE PART NUMBERS ON THE ART WORK TO AGREE WITH THE TEXT OF THE BULLETIN.

Some of the above vehicles may exhibit the subject condition at engine speeds ranging from idle to 1700 rpm.

If customer comments are received on this condition, it may be addressed by the installation of a new mounting brace for the A/C compressor and the addition of a new muffled A/C hose assembly.

This new hose assembly may be used in conjunction with the installation of a new compressor brace or it may be added for additional noise improvement to a vehicle that already has the brace installed.

The 1990 early Production vehicles with the 3.1L engine should have the compressor brace but not the new muffled A/C hose assembly. Breakpoints are not available at this time.

The part numbers for the A/C brace, attaching parts, A/C hose assembly and the installation procedure are as follow:

Quantity Part Number Part Name

1 10137014 Brace - A/C Compressor 1 22533540 Bolt/Screw 2 14056165 Bolt/Screw 1 10146913 Hose Assembly A/C Compressor Condensor

Procedure:

1. Disconnect the negative battery cable.

IMPORTANT: If the vehicle is already equipped with the new compressor mounting brace, omit steps 2 thru 5 and go to step 6.

2. Loosen the belt tensioner and remove the belt from the A/C compressor.

3. Remove the two front mounting bolts of the A/C compressor.

4. Install the new brace and the three new mounting bolts, as shown in Figure 1.

5. Reinstall the belt and tighten the tensioner.

6. Discharge the A/C System.

7. Remove the A/C hose assembly.

8. If the vehicle is equipped with the compressor brace, as shown in Figure 2, it should be removed and discarded before the installation of the new A/C hose assembly. This brace is no longer needed.

9. Install the new A/C hose assembly.

10. Recharge the A/C system with the required amount of A/C refrigerant.

11. Connect the negative battery cable.

12. Perform engine idle learn procedure as per Service Manual, Section 6E3-C2-7.

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.