OPERATION & LEAKAGE TESTS
1.Test the outlet port check valve assembly by building the air system to governor cut-out and observing a test air gauge installed in the #1 reservoir. A rapid loss of pressure could indicate a failed outlet port check valve. This can be confirmed by bleeding the system down and removing the check valve assembly from the end cover. Once this has been done, subject air pressure to the unit and apply a soap solution to the check valve side. Leakage should not exceed a 1” bubble in 1 second.
2.Check for excessive leakage around the purge valve. With the compressor in loaded mode (compressing air), apply a soap solution to the purge valve housing assembly exhaust port and observe that leakage does not exceed a 1” bubble in 1 second. If the leakage exceeds the maximum specified, service the purge valve housing assembly.
3.Close all reservoir drain cocks. Build up system pressure to governor cut-out and note that the air dryer purges with an audible escape of air. “Fan” the service brakes to reduce system air pressure to governor cut-in. Note that the system once again builds to full pressure and is followed by an air dryer purge.
