A/C - Noisy/Inoperative: Overview
File In Section: 01 - HVACBulletin No.: 01-01-39-002B
Date: December, 2001
TECHNICAL
Subject:
Noise in Engine Compartment with Air Conditioning (A/C) On, A/C System Inoperative (Install Redesigned Rear A/C Suction Hose, Replace Compressor)
Models:
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).
Condition
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.
Cause
Under certain driving conditions, the A/C compressor may be starved of oil.
Correction
Important:
Do NOT use Rear Auxiliary A/C Line P/Ns 15065471 and 15065472.
Important:
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
^ 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 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
Important:
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.
Front circuit
1. Recover the system refrigerant.
2. Remove the expansion device (TXV or orifice tube) from the front circuit.
3. Re-connect the A/C lines with the orifice tube removed or install the appropriate non-blocked (open) TXV Adapter from kit J 45268.
Important:
A blocked orifice tube is not supplied with the J 45268 Adapter kit. A blocked orifice can be made using the following steps:
3.1. Cut the orifice tube frame and screen.
3.2. Remove enough of the frame and screen to access the end of the orifice tube.
3.3. Seal the tube by pinching off the end of the orifice tube.
4. Remove the expansion device (TXV or orifice tube) from the rear circuit and install a plugged expansion device (TXV or orifice tube) into the rear circuit.
5. Remove the A/C compressor. Refer to the service procedure below.
6. Install the appropriate A/C compressor hose assembly flush adapter(s) from kit J 45268.
7. Configure the flush adapter and hose for either a forward flush or reverse flush. Refer to the Flushing Configuration below.
8. Perform the flush of the front system by following the instructions supplied with the J 43600 ACR 2000.
9. Replace the plugged expansion device (TXV or orifice tube) in the rear circuit with an open expansion device (TXV or orifice tube).
10. Replace the open expansion device (TXV or orifice tube) in the front circuit with a plugged expansion device (TXV or orifice tube).
11. Flush the rear system by following the instructions supplied with the J 43600 ACR 2000.
Flushing Configuration - Forward Flush Forward
Flushing (the same flow as normal system operation) is recommended for contaminated refrigerant or PAG oil.
Important:
^ Install a new filter inside the J 45268-1 for every flush. Service the filter with P/N 5651802 (in Canada, use P/N 729832). Remove and discard the check valve filter from the filter.
^ Always close the valve on the J 43600 ACR 2000 external refrigerant tank before starting the flush process.
1. Connect the flush filter adapter J 45268-1 to the suction port of the A/C compressor hose assembly flush adapter.
2. Connect the blue hose from the J 43600 ACR 2000 to the J 45268-1 flush filter adapter.
3. Connect the red hose from the J 43600 ACR 2000 to the discharge port of the A/C compressor hose assembly flush adapter.
4. Follow the instructions supplied with the J 43600 ACR 2000 and flush the A/C system.
Flushing Configuration - Reverse Flush
Reverse flushing (the opposite flow of normal operation) is recommended for desiccant bag failure. Always replace the accumulator after the reverse flushing procedure is complete.
Important:
^ Install a new filter inside the J 45268-1 for every flush. Service the filter with P/N 5651802 (in Canada, use P/N 729832). Remove and discard the check valve from the filter.
^ Always close the valve on the J 43600 external refrigerant tank before starting the flush process.
1. Connect the J 45268-1 flush filter adapter to the discharge port of the A/C compressor hose assembly flush adapter.
2. Connect the blue hose from the J 45268-1 flush filter adapter.
3. Connect the red hose to the suction port of the A/C compressor hose assembly flush adapter.
4. Follow the instructions supplied with the J 43600 ACR 2000 and flush the A/C system.
Important:
Refer to Corporate Service Bulletin Number 01-01-38-006A (SI 2000 Document ID # 803991) for additional flushing information.
Parts Information
Parts are currently available from GMSPO.
Warranty Information
For vehicles repaired under warranty, use the table as shown.
DISCLAIMER