For 1990-2009 cars

# Water in AIR Pump and/or DTC 48 (Install AIR Pump Service Kit)

Subject: | Water in AIR Pump and/or DTC 48 (Install AIR Pump Service Kit)

Models: | 1994 Buick Roadmaster

| 1994 Cadillac Fleetwood

| 1994 Chevrolet Caprice

| with 4.3 L or 5.7 L V8 Engine (VINs W, P -- RPOs L99, LT1)

This bulletin is being revised to delete reference to 1995 and 1996 vehicles. Please discard Corporate Bulletin Number 77-65-13 (Section 6 -- Engine).

### Condition

Some customers may comment on a hesitation during heavy/full throttle acceleration. Some vehicles may also set a DTC 48. There will also be evidence of water in the AIR Pump.

### Cause

Under high engine speed and load conditions, hot exhaust gasses may leak past the AIR check valves. As the exhaust gasses in the in the air tube cool, water vapors collect into the AIR Pump. When the vehicle is driven, condensation from the AIR Pump may come into contact with the mass air flow sensor. This condition may cause a hesitation on acceleration and may also set the DTC.

### Correction

Verify AIR Pump operation using a scan tool. Inspect the AIR Pump for traces of water. If the AIR Pump shows indication of water intrusion, install an AIR Pump service kit.

Important: Inspect the AIR check valves by using a hand vacuum pump. Apply 10 inches of vacuum to the AIR hose side of the check valve. Vacuum should hold for at least 10 seconds. If not, replace the AIR check valves.

### Parts Information

Part Number | Description | Qty
--- | --- | ---
12558522 | AIR Pump Service Kit | 1
22048212 | AIR Check Valves | 2
12554580 | AIR Pump | 1

Parts are currently available from GMSPO.

The AIR Pump Service Kit, P/N 12558522 includes:

Description | Qty
--- | ---
Installation Instructions with Art | 1
AIR Shut Off Valve | 1
Solenoid, For AIR Pump Shut Off Valve | 1
Hex Washer Nut for Solenoid | 1
Hose, AIR Pump to Shut Off Valve | 1
Vacuum Line, Shut Off Valve to Solenoid | 1
Vacuum Line, Intake Manifold to EGR Solenoid | 1
Wire Harness, AIR Solenoid to AIR Pump | 1
Wire Harness Cap | 1

### Warranty Information

For vehicles repaired under warranty, use:

Labor Operation | Description | Labor Time
--- | --- | ---
J6050 | AIR Pump | 0.3 hr.
J6068 | AIR Check Valves | 0.2 hr.
Add to J6050 | AIR Pump Service Kit | 0.8 hr.