Residual Air Pressure Check - ALC

RESIDUAL AIR PRESSURE CHECK

^ Tools Required
- J22124-B Pressure Gage
- J22124-91 Pressure Gage Adapter

The air dryer is equipped with valving that maintains a residual pressure of 48 - 97 kPa (7 - 14 psi) in the shock absorbers to improve ride characteristics during light load conditions. Additionally, shock absorber air sleeve life is improved when the Automatic Level Control (ALC) system maintains residual air pressure. The following steps must be followed to perform the "Residual Air Pressure Check" properly.

1. Raise the vehicle. Refer to Vehicle Lifting.

NOTE: The vehicle must be raised on a drive-on lift or be supported at the rear under the rear axle. Full vehicle weight must be on the rear suspension.

2. Disconnect the air tube from the air dryer.
3. Connect the J22124-91 to the air dryer.
4. Connect the J22124-B to the J22124-91. Open the J22124-B toggle valve.
5. Disconnect the air tube from one shock absorber.
6. Connect the adapter tube supplied with J22124-B to the shock absorber and to the J22124-B.
7. Disconnect the link from the height sensor and move the arm up. The air compressor should operate, inflating one shock absorber.
8. Move the arm down. The air compressor should stop and air should be escaping. Allow the rear of the vehicle to go down as far as possible.
9. Connect the link to the height sensor.
10. Read the pressure gage.
If the pressure gage reads less than 48 kPa (7 psi). replace the air dryer. Refer to Air Dryer Replacement.
11. Disconnect the J22124-B and J22124-91 from the air dryer and shock absorber.
12. Connect the air tube to the air dryer and the shock absorber.
13. Lower the vehicle. Refer to Vehicle Lifting.