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.
- Place the air suspension system in Park Mode (Entry/Exit).
- Raise and support the vehicle. Refer to HOISTING, STANDARD PROCEDURE .
- 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 front springs. When in the Spring Deflate to Atmosphere menu, choose to "completely deflate" for each of the front springs.
- With a diagnostic scan tool, under the Air Suspension Control Module (ASCM) run the "Deflate to Atmosphere" routine and select "Reservoir 2 Only (Fast Down Leveling Reservoir)" then "Complete Deflate".NOTE: This routine will deflate the reservoir to a predefined pressure set point. It may be necessary to loosen air line fittings to release residual air pressure.
- Disconnect the fast down leveling valve wire harness connector.
1 - Fast Down Leveling Valve Nuts 2 - Wire Harness Connector 3 - Fast Down Leveling Valve Air Line Nuts - Remove the fast down leveling valve air line nuts and disengage the air lines from the fast down leveling valve.
- Remove the fast down leveling valve nuts and 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 .