A/C System - Insufficient Cooling

Group: 87

Number: 94-02

Date: Sept. 22, 1994

Subject:
A/C System Insufficient Cooling, with variable displacement compressor

Model(s):
Golf III, Jetta III, Jetta GLX, Cabrio, Passat, Corrado
From m.y. 1993

Condition

Insufficient cooling caused by blockage in one of the A/C components. This condition cannot be identified by A/C system pressure checks since the compressor regulates the pressure to a medium value.

Service

^ Check the evaporator for blockage. With A/C on, feel along the evaporator starting from the inlet to the outlet for surface temperature uniformity A cold spot may be present in area of blockage.

^ If surface temperature is not uniform remove evaporator and recheck. Blow out evaporator blockage with compressed air.

^ If evaporator is free of blockage flush it with nitrogen to remove any moisture.

^ Replace evaporator if blockage cannot be removed with compressed air.

^ If blockage was not observed in the evaporator, remove and inspect each A/C component. Use compressed air to dislodge any blockage. Afterward, flush components with nitrogen to remove moisture.

^ Replace components that contain residue and could not be cleaned completely.

^ If blockage was not observed anywhere in the system, replace the expansion valve.

Note:
Replace the receiver drier after performing this repair.