Residual Air Check

The air dryer has a valve arrangement that maintains approximately 8---24 psi in the air shocks to improve the vehicle's ride characteristics under light load conditions. To test this condition, proceed as follows:
1. Disconnect air line from the dryer assembly and attach it to one side of pressure gauge 0-2070 (0---300 psi), or equivalent.
2. Attach a short piece of bulk nylon tubing from the dryer to the other side of the pressure gauge. A compressor ball sleeve nut and sleeve for {3-16} inch tubing with ball sleeve connector and an internal pipe T fitting can be used to attach the tubing to the pressure gauge.
3. Cycle ignition switch from OFF to ON position.
4. Apply a load of approximately 300---350 lbs. to operate compressor and raise the vehicle.
5. Remove load applied in step 4. Allow the system to exhaust and lower the vehicle.
6. When no more air can be exhausted, the gauge should indicate 8---24 psi.
7. Remove pressure gauge. Attach the system air line to the dryer and repeat steps 3, 4 and 5 to ensure system air pressure is within the shocks.