Isolating Compressor
WARNING: This page does not describe the selected car, but rather 124 other vehicles, including the 1991 Volvo 940, 1991 Volvo 740, 1991 Volvo 240, 1991 Volkswagen Vanagon, and 1991 Volkswagen Passat. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
When discharging air conditioning system, use only approved refrigerant recovery/recycling equipment. Make every attempt to avoid discharging refrigerant into the atmosphere.
NOTE:
Only compressors with stem-type service valves can be isolated.
- Connect service gauge set to the compressor service valves and open compressor valves slightly (turn in clockwise). Start engine and operate air conditioning. Slowly turn compressor suction valve clockwise toward closed (front-seated) position.
- When suction pressure is reduced to zero or less, turn off engine and compressor and quickly turn suction valve stem in to full front-seated position. Suction pressure should be slightly above zero. Turn discharge valve into front-seated position.
- To check oil level, slowly open compressor crankcase plug to relieve any remaining pressure. After oil level is corrected, cap service gauge ports on both valves. Back-seat suction service valve to allow refrigerant to enter compressor. Open discharge valve halfway.
- Loosen discharge service valve cap, allowing refrigerant pressure to force air out of compressor. Back-seat service valve and tighten cap. Compressor is now ready for operation.