I can't locate the check valve on my LeRoi Dresser air compressor.
(Duncannon PA USA)
LeRoi Dresser air compressor
Hi, I have an older LeRoi 80 gallon air compressor with a Dresser 500 2 stage compressor. It is leaking air through the bottom port of the unloader valve when the pump shuts off. The unloader doesn't seem to be unloading either. It is locate on the front of the compressor pump.
Reading through the posts on your site it would seem that the best place to start is by examining the check valve. The problem is that I can't find anything that looks like a check valve between the pump and the tank or between the pressure switch and tank.
There is a copper line between the high pressure cylinder and the tank. On either end of the line is what appears to be a 90 degree gas line compression fitting.
The pressure switch is plumbed into a standard looking pipe "T" which is plumbed to a pipe nipple going to the tank. There is a plastic line plumbed into the pipe "T" below the pressure switch that runs to the unloader valve.
There are 2 small copper lines that run from each of the cylinders to a "T" and then to the unloader valve. Nothing looks like any pics I have seen of a check valve.
Any thoughts would be appreciated. I can send pics as well. Thanks, Tim.