K 3500 Truck 4WD V8-6.6L DSL Turbo VIN 1 (2001)
Technical Service Bulletin # 01-01-39-002B
A/C - Noisy/Inoperative
File In Section: 01 - HVAC
Bulletin No.: 01-01-39-002B
Date: December, 2001
Noise in Engine Compartment with Air Conditioning (A/C) On, A/C System Inoperative (Install Redesigned Rear A/C Suction Hose, Replace
2000-2001 Chevrolet and GMC C/K Utility Models Built Prior to October 10, 2000 With Auxiliary Rear A/C (RPO C69)
This bulletin is being revised to add additional procedure information. Please discard Corporate Bulletin Number 01-01-39-002A (Section 01 - HVAC).
Some customers may comment on excessive noise from the engine compartment with the A/C on. Some customers also may comment that the A/C
system is inoperative.
Under certain driving conditions, the A/C compressor may be starved of oil.
Do NOT use Rear Auxiliary A/C Line P/Ns 15065471 and 15065472.
Flushing the A/C System After Catastrophic Compressor Failure
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. System flushing requires prior authorization by the GM Area Service Manager (in Canada,
the District Service Manager) and should be performed only when any one of the following conditions is found.
Desiccant bag failure
Gross overcharge of PAG oil
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 to control this type of system contamination and avoid repeat failures.
A warm engine compartment or higher ambient temperatures speed the refrigerant recovery time during the A/C flush procedure. Whenever possible,
warm the engine prior to system flushing.
Front/Rear (Dual Circuit) A/C Systems
Each circuit of a front/rear A/C system must be flushed separately. Flow to one circuit must be blocked with the use of a blocked orifice tube or
blocked TXV. The front circuit should always be flushed first.