# Pressure issues with quincy 325



## dillpickle02 (6 mo ago)

picked up a very old quincy 325 a year ago for free, I've finally decided to work on it and replaced the motor with a probably underpowered gas engine. It worked great when running unloaded, but once we closed off the tank and let it build pressure at around 38-40 psi a valve on the top of the compressor started letting out air and then the engine stalled and wouldn't start again. It kept on emptying air until the entire tank drained. Not exactly sure what is the cause of this but any ideas would be grateful.


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## MacMcMacmac (9 mo ago)

If it does this with the air line connected to the top of the tower, either the hydraulic unloader valve is not sealing properly, or you are low on oil pressure. If it does this without the air line attached, the piston inside that tower is seized in the unloaded position, or the o-ring on it has failed.


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