Air Dryer: Testing and Inspection

The air dryer has a valve arrangement designed to maintain a minimum pressure of 25-40 psi. To check this function, proceed as follows:

Fig. 44 Installing Pressure Gauge:

1. Remove air line from dryer fitting and strut or spring. Attach a piece of bulk nylon tubing to one side of a suitable 0-300 psi pressure gauge and the strut or spring solenoid.
2. Attach another piece of nylon tubing from dryer to the other side of the pressure gauge. A compression 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. Activate compressor by grounding pin S08 to pin X20. Cycle unit and read air pressure. Pressure of 25-40 psi indicates that the system and the compressor are acceptable.