Fast Down Leveling Valve: Notes
REMOVAL
All pressurized air suspension components contain high pressure air (up to 220 psig). Use extreme caution when inspecting for leaks. Wear safety goggles and adequate protective clothing when inspecting or servicing the air suspension system. A sudden release of air under this amount of pressure can cause possible serious or fatal injury.
Before performing any service on the air suspension system, the system must be disabled to prevent the system from changing ride height. Before any given component is to be serviced it must be deflated. Servicing the air suspension system without the system disabled, or with pressure in any specific component, can cause possible serious or fatal injury.
When removing an air line from a component and the air line is to be reused, do not remove the 90° fitting or the brass fitting from the air line. If either is removed, the air line must be replaced. Do not remove protective caps or plugs from air lines or components until ready to install the air line to prevent moisture or dirt intrusion. All air line fittings must be hand started to avoid cross threading.
The air suspension system can be disabled and enabled by using the Display Screen Module (DSM) in the vehicle under Tire Jack Mode, which is the preferred method. If the disable level control routine in the diagnostic scan tool is used it will only disable the level control (automatic and manual) for that ignition cycle. The air suspension system can also be enabled by driving the vehicle above 19 km/h (12 mph). The air suspension should be disabled prior to lifting the vehicle or performing any work.
- Place the ignition in the ON position.
- Place the air suspension system in Park Mode.
- With a diagnostic scan tool, using the routines under the Air Suspension Control Module (ASCM), perform the following:
- Disable the air suspension system. Refer to DISABLING AND ENABLING AIR SUSPENSION .
- Run the Spring Deflate To Atmosphere routine on each of the four springs. When in the Spring Deflate to Atmosphere menu, choose to "completely" deflate for each of the four springs.
- Place the ignition in the OFF position.
- If equipped, remove the front skid plate. Refer to PLATE, SKID, REMOVAL AND INSTALLATION .
- Raise and support the vehicle. Refer to HOISTING, STANDARD PROCEDURE .
- Perform the manual reservoir deflate. Refer to MANUAL RESERVOIR DEFLATE .
- If equipped, remove the active air dam. Refer to AIR DAM, FRONT, REMOVAL AND INSTALLATION
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1 - Fast Down Leveling Valve Air Line Nuts 2 - Fast Down Leveling Valve Wire Harness Connector 3 - Fast Down Leveling Valve Bolts - Disconnect the fast down leveling valve wire harness connector.
- Remove the fast down leveling valve air line nuts.
- Remove the fast down leveling valve bolts.
- Remove the fast down leveling valve.
INSTALLATION
Follow the removal procedure in reverse for general reassembly of the components on the vehicle. The steps listed below are calling out specific procedures that should be followed during installation.
- Perform the Complete System Fill standard procedure. Refer to COMPLETE SYSTEM FILL .
- With a diagnostic scan tool, using the routines under the Air Suspension Control Module (ASCM), perform the following:
- Run the Air Mass Calculation routine on the air suspension system.
- If necessary, add to the system or deflate to atmosphere using the ASCM routines, then repeat the Air Mass Calculation routine again until the system is Normal.
- Enable the air suspension system.
- Perform the ASCM Verification Test. Refer to ASCM VERIFICATION TEST .