Just today I observed something odd on my YH. It's working fine but a few seconds after it is shut down, I noticed some faint hissing sound coming out from the low-pressure relief valve ( the one with a red plastic cover and a ring ). The hissing stops once the high pressure end is bleeded.
The only reason I can think of is the check valve between the first and second stage leaking. When the compressor is running, air is constantly being sucked away by the second stage so excessive pressure cannot be built up in the first stage. Once the compressor stops running, air on the high pressure side can flow back to the low-pressure side , apparently quite slowly in my YH resulting in pressure build-up in the low pressure end and the relief valve being activated.
What do you guys think ? Is this the likely reason ? anything I may have missed ?
The only reason I can think of is the check valve between the first and second stage leaking. When the compressor is running, air is constantly being sucked away by the second stage so excessive pressure cannot be built up in the first stage. Once the compressor stops running, air on the high pressure side can flow back to the low-pressure side , apparently quite slowly in my YH resulting in pressure build-up in the low pressure end and the relief valve being activated.
What do you guys think ? Is this the likely reason ? anything I may have missed ?