Height Control Valve
- Remove control valve from vehicle and clean exterior. Connect test gauge and air pressure source to intake adapter and apply 80-110 psi. Submerge unit in water. With overtravel lever in neutral position, no air should escape. If there are bubbles from shock absorber port, replace valve.
- Shut off air pressure and disconnect test gauge. Plug intake port with suitable adapter, connect test gauge to shock absorber port and apply air pressure. With overtravel lever in neutral position, no air should escape. If air escapes from exhaust port, replace valve. If air escapes around edge of cover plate, tighten screws or replace gasket. Remove control valve from water and actuate overtravel lever to expel any water, then remove test gauges and air line.