General Information

This article has been updated with bulletin No. 01-01-38-006A.

CONTAMINATED R-134A A/C SYSTEMS - AIR CONDITIONING SYSTEM FLUSHING PROCEDURES AND GUIDELINES
A/C system flushing should NOT be routinely performed when a system failure is encountered. System flushing takes a considerable amount of time to perform and is NOT necessary on most system failures and should be performed only when any one of the following conditions is found.
- Desiccant bag failure
- Gross overcharge of PAG oil
- Refrigerant contamination
- Contaminated PAG oil
- Catastrophic compressor failure causing oil contamination






A/C system flushing will remove some of the metal particles during a flush, but flushing is not completely effective in removing all metallic debris. System flushing should not be considered if removal of metallic debris is the only objective. GM Service Operations continues to recommend the use of LIQUID LINE FILTERS and SUCTION SCREENS to control this type of system contamination and avoid repeat failures.