Quincy 325 Air Compressor unloader leak

[16sierra]

I recently put a Quincy 325 ROC 101 back into service. I did not to a complete tear down and clean/rebuild. I've found that I have pretty bad leaks on both unloader towers around the gaskets. Will new gaskets fix this or would something in the check valves inside the towers also be contributing? I did put a check valve in between the pump and tank. I know they're not needed on this pump but I've found them to be reliable in the past and thought it would help hold pressure in the tank more reliably.

 

[gizardlizard]

For years at work, I maintained a pair of Quincy 5120’s. 4 towers on each compressor. The diagrams were a constant problem with cracking and leaking. I keep a box of a dozen diagram gaskets on hand at all times because we changed them so often.