A/C Compressor Oval O-Ring - Seal
89Pontiac20Bulletin Number: 90-1-2
Reference Number: 931204
Publish Date: 9/89
Subject: A/C COMPRESSOR OVAL O-RING SEAL (DESIGN INFORMATION)
Models
Affected: 1988-90 ALL MODELS WITH R4, HR6 AND V5 A/C COMPRESSORS
Figure 1:
Figure 2:
Figure 3:
During the 1988 model year, approximately June 1, 1988, the cross section design of the A/C compressor O-rings was changed from the standard round type to an oval type design.
Parts are currently available from GMSPO.
The reason for the design change was to improve the durability of the compressor refrigerant joint. It is important to understand, that due to the cross section shape of the oval versus the round design (see Fig. 2), the oval O-ring does not completely fill the machined O-ring groove in the compressor rear head (see Fig. 1). A gap between the oval O-ring inside diameter and the machined groove inside diameter is correct and expected.
In addition, the oval O-ring does not fit freely in the O-ring groove. The O-ring must be coated with approved refrigerant oil and inserted all the way into the O-ring groove prior to the joint assembly.
The service part numbers for the oval O-rings are shown in both Fig. 2 and Fig. 3.