I picked up an old US Air Compressor dual stage MK series pump with a 2 HP GE repulsion induction motor. I just finished mounting it all up to a SAFE newer certified 200 psi vertical tank. The compressor runs beautifully and sounds very smooth and quiet until the tank gets beyond 60-80 PSI at which point the motor starts making noise which looks to be the entire shaft and pulley "walking" back and fourth. I originally thought it might be a symptom that started once things were hot but I have aired it up and let it cool off and it does the same thing, I also purged the tank while it is hot and everything returns to smooth and quiet operation.
Not sure if it is related but I know this compressor originally had a centrifugal unloader but that appears to have been disabled, the small line connecting from the output line to the front of the compressor has been removed and it looks like there is a simple inline check valve presumably to account for the disabled unloader?
The flywheel seems to have a little wobble to it beyond 60 psi. I am guessing the pump itself could be the culprit with either worn bearings or something related to the unloader causing the wobble. Any help would be greatly appreciated.
Not sure if it is related but I know this compressor originally had a centrifugal unloader but that appears to have been disabled, the small line connecting from the output line to the front of the compressor has been removed and it looks like there is a simple inline check valve presumably to account for the disabled unloader?
The flywheel seems to have a little wobble to it beyond 60 psi. I am guessing the pump itself could be the culprit with either worn bearings or something related to the unloader causing the wobble. Any help would be greatly appreciated.