Expedition 4WD V8-4.6L SOHC VIN W (1999)
Level Control Solenoid Valve: Technical Service Bulletins
Air Suspension - Repeat Compressor Drier Failures
Article No.
03-9-2
05/12/03
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SUSPENSION - REPEAT AIR SUSPENSION COMPRESSOR DRIER FAILURES
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ELECTRICAL - REPEAT AIR SUSPENSION COMPRESSOR DRIER FAILURES
FORD:
1997-2002 EXPEDITION
LINCOLN:
1998-2002 NAVIGATOR
Article 03-7-9 is being republished in its entirety to update the Service Procedure.
ISSUE
Some 1997-2002 Expedition 4X4 and 1998-2002 Navigator 4X4 vehicles equipped with 4-wheel air suspension, may exhibit repeat air compressor drier
failures. The drier cap may become detached from the drier body, or the drier body may be broken at the neck near the compressor head. This may be
due to incomplete or incorrect system diagnosis that leads to replacement of only the original air suspension compressor, despite the fact that the
compressor is not the root cause of the concern. Compressor failure in these instances is only a symptom of an underlying system problem.
ACTION
Refer to the service information contained in this TSB for information on proper diagnosis of system issues. Be sure to check the system for proper
pneumatic function as described during service to ensure a robust repair.
SERVICE INFORMATION
Overview
Proper pneumatic function can be tested by verifying that both the front AND the rear of the vehicle can be raised and lowered one inch using a scan
tool, and by monitoring the height sensor PIDs for movement while the vehicle is in the service bay. If the vehicle does not raise and lower normally,
check the solenoid valves and air lines for blockages and/or restrictions. Replace any blocked or restricted solenoids and air lines. ALWAYS check for
proper pneumatic function before returning the vehicle back to the customer.
NOTE
DISCONNECTING AN AIR LINE THAT IS CONNECTED TO THE AIR COMPRESSOR CAN CAUSE PERSONAL INJURY OR DAMAGE
TO COMPONENTS AS HIGH PRESSURE IS VENTED UNCONTROLLED.
If diagnostics lead to compressor/dryer assembly replacement, use the following service procedure to insure complete and thorough service.
1.
Using the New Generation STAR (NGS) tester, vent the compressor/drier assembly.
2.
Using regulated shop air, blow out the air lines from the drier to the front fill solenoid valve and from the drier to the rear fill solenoid valve,
before installing the new compressor assembly.
3.
Replace the air suspension compressor assembly. Refer to Workshop Manual Section 204-05 for compressor installation instructions.
4.
Replace the front fill solenoid. Refer to Workshop Manual Section 204-05 for replacement instructions. The front fill solenoid must be replaced
because in these cases, it may have sustained damage from the drier desiccant or other contaminants.
5.
Connect the New Generation STAR (NGS) tester to the vehicle while the vehicle is parked in the service bay with the engine running.
