A/C - Insufficient Performance Using Front System Only

File In Section: 1 - HVAC

Bulletin No.: 63-12-07

Date: May, 1996

Subject:
Insufficient A/C Performance (with C34 - Rear A/C) When Using Front System Only (Add 1/4 lb R134a to System)

Models:
1996 Chevrolet Lumina APV
1996 Oldsmobile Silhouette
1996 Pontiac Trans Sport
with Rear A/C (RPO C34)
Built Prior to the following VIN Breakpoints:

Model VIN Breakpoint

Lumina APV 117248
Silhouette 306374
Trans Sport 212925

Condition

Some owners of the above listed vehicles with the rear A/C option, RPO C34, may comment on insufficient air conditioning performance when using the front system only.

Cause

This condition may be caused by refrigerant bleeding through the rear TXV and being captured in the rear evaporator and suction line. When this happens, the front system is starved of refrigerant and results in poor air conditioning performance from the front system.

Correction

This condition may be corrected by adding an additional 1/4 lb (0.25 lb) R134a to the system for vehicles built prior to the above identified VIN breakpoints. Vehicles built after these breakpoints will include the additional 1/4 lb (0.25 lb) charge.

Important:
Future service to the A/C system on any 1996 U Van should include the additional 1/4 lb (0.25 lb) charge.

Procedure

Recover the existing R134a, then evacuate and re-charge the system to include the additional 1/4 lb (0.25 lb).

Warranty Information

For vehicles repaired under warranty, use:

Labor Operation Labor Time

T2042 0.7 hr