Hydrovane Compressor Noise

[flatlandfarmer]

Recently brought a used Hydrovane PU23. Is it normal for these to make a boiling/bubbling noise like a kettle once they are switched off? Haven't quite got around to understanding how these compressors work, to know if this noise is normal?

 

[Zebbedee]

Don’t know a huge amount about compressors but I would firstly wh3n you stop the compressor open a tap and dump all the air, if the boiling bubbling noise stops investigate air side. But more likely water in engine cooling is the culprit so very slowly and cautiously check radiator cap, do not burn yourself if engine is likely to be at operating temperature

 

[Jon]

On my Hydrovane that's an engine powered one, the instructions are to not release pressure when shutting down


I can hear something on the pump side while the pressure gradually reduces.

Is your oil level correct in the pump ?