A/C COMPRESSOR SEALING WASHER USAGE (NEW DESIGN)

SUBJECT: AIR CONDITIONING COMPRESSOR SEALING WASHER USAGE (NEW PARTS)

MODELS: 1988-92 ALL TRUCKS

There has been a redesign of the GM Harrison A/C compressor rear head and the mating face of the attaching hose assembly. The redesign eliminates the two O-ring seals from the compressor, replacing them with two "sealing washers added to the suctional discharge hose set". Each sealing washer consists of a metal washer with an integral molded rubber seal (refer to illustrations).

THE O-RING AND SEALING WASHER DESIGNS ARE NOT INTERCHANGEABLE. The compressor design will determine which type of washer to use.

- Use sealing washers on compressors with suction discharge ports having a flat sealing surface.

- Use O-ring seals on compressors with O-ring grooves in the suction discharge port sealing surface.

A service compressor ordered from GMSPO may be of either design. If the compressor uses the seating washers, the washers will be included with the service compressor.

Use of improper seals may result in damage to the seals and cause leaks.

SERVICE INFORMATION:

Lubrication of sealing washers is neither required nor recommended. Follow the installation instructions included with the parts kits below.

When using sealing washers, there will be an intentional "gap" between the compressor rear head and the air conditioning hose assembly block (suction discharge block assembly). Do not mistake this as a loose connection or a mis-assembled joint.

Sealing washers are used in production on all 1992 vehicles.

PARTS INFORMATION:

Seal or Gasket - A/C Compressor Sealing Washer, Service Kits:

Part Number Application ------- ----------------------------------- 2724575 All pre-1992 compressors 2724577 All 1992 compressors with 5/8" suction port openings 2724578 All 1992 compressors with 3/4" suction port openings

Parts are currently available from GMSPO.

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.