The valve is a common replacement part; however, many times customers purchase the valve prematurely.
Air leaks from the mufflers so they assume it is the valve; however, the leak could be a result of air bypassing the piston inside the cylinder. (think of head gasket crack).
To test if the valve is bad or if the cylinder seals are bad perform the following:
1. Disconnect the machine from air supply
2. Disconnect 1 of 2 air lines that supply the cylinder
3. Reinstall the air supply to the machine.
4. From the side that the air line was, there should not be any air coming from the fitting.
-If air is being release from the air hose, simply press and hole down the foot pedal to change the direction of the air flow.
5. If air dose NOT come out from the fitting and you still hear air leaking from the valve, then the valve is BAD. If air DOSE come out from the fitting (even a small amount) then the cylinder
needs to be rebuilt.
Depending on the age of the machine and its environment it could be both valve and cylinder seals have worn out. "You fixed one than to only expose there was another problem.”