Complete System Fill
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.
Support the vehicle by supplemental means before performing any work on the air suspension system to prevent the vehicle from changing height. Before any given component is to be serviced it must be deflated. Servicing the air suspension system without supplemental support, or with pressure in the specific component, can cause possible serious or fatal injury.
The air suspension system will auto-disable when lifted on a frame hoist, or when jacking one corner of the vehicle. The air suspension may attempt to change height slightly prior to switching to auto-disable. A manual disable is also available by pressing the "Up" and "Down" switches simultaneously for more that 5 seconds. The air suspension system will return to normal operation when the vehicle speed reaches 25 kph (15 mph).
This procedure should only be necessary when the entire system was purged of air, as in a compressor or valve block assembly replacement.
The gauge (1) on Air Suspension Refill Tool - (special tool #10247, Tool, Air Suspension Refill) reads the tank pressure. The regulator limits the pressure in the line (4) to 12 bar (175 psi). When connected to the reservoir with the valves open, pressure in the reservoir can be read on the scan tool.
The Air Suspension Refill Tool - (special tool #10247, Tool, Air Suspension Refill) (1, 4, 5, 6) is used with a nitrogen supply tank (2, 3) which can be acquired at a local gas supplier. The nitrogen must be Purity Class 5 (99.999% pure) .
- Raise and support the vehicle so the suspension system is hanging (four wheels off the ground). Refer to HOISTING, STANDARD PROCEDURE .
- Make sure the Air Suspension Refill Tool - (special tool #10247, Tool, Air Suspension Refill) line on/off valve (6) is turned off and the nitrogen tank valve is turned off (2).NOTE:
With the air suspension reservoir under the pickup box, the fill fitting will always be on the passengers side of the vehicle.
- Remove the RR inner wheel liner to expose the reservoir.
- Remove the reservoir fill connection cap (not shown in illustration).
- With Air Suspension Refill Tool - (special tool #10247, Tool, Air Suspension Refill) (1, 2, 5) attached to a nitrogen tank, connect the quick coupler (2) to the air suspension reservoir fill connection (3) and open the valve (1) by turning clockwise.
- Fill the reservoir to approximately 12 bar (175 psi) by fully opening the valve (2) on the nitrogen tank (3) and the valve (6) on Air Suspension Refill Tool - (special tool #10247, Tool, Air Suspension Refill) (1, 4, 5, 6).
- When the pressures are equalized, close the valve (6) on the tool.
- With a scan tool, using the routines under the Air Suspension Control Module (ASCM), perform a Short Fill on one rear air spring, verify that the air spring is seated properly, then perform a Complete Fill on that spring.
- Repeat step 8 on the opposite rear air spring.
- Fill the reservoir again by repeating steps 6 and 7.
- With a scan tool, using the routines under the Air Suspension Control Module (ASCM), perform a Complete Fill on each front spring and shock assembly.
- Verify the Air Suspension Refill Tool - (special tool #10247, Tool, Air Suspension Refill) line on/off valve (6) is closed and close and the nitrogen tank valve (2).
- Remove the supports and lower the vehicle.
- Close the valve (1) by turning counter clockwise, remove the quick coupler (2) from the air suspension reservoir fill connection (3) and install the reservoir fill connection cap (not shown in illustration).
- With a scan tool, using the routines under the Air Suspension Control Module (ASCM), perform the following:
- Command the vehicle to Normal Ride Height.
- 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 system responds with Air Mass OK (188 - 216 bar-liters).
- Perform the ASCM Verification Test. Refer to STANDARD PROCEDURE . .
The regulator on Air Suspension Refill Tool - (special tool #10247, Tool, Air Suspension Refill) is preset to 12 bar (175 psi) (as read with a scan tool, the gauge reads tank pressure only). When connected to the reservoir and the valves open, the pressure will equalize to 12 bar (175 psi) in approximately 10-15 seconds. A hissing sound can be heard while the nitrogen is being transferred and the sound will stop when the pressures are equalized.