Problem with the non return valve
I bought a seccond hand compressor over from someone, it looks to be a good buy, but their is one problem.
When i turned the compressor on for the first time it ran for a minute or two then the motor started labouring, i then switched it off and removed the belt and let the motor run freely, the motor was fine but the wheel on the pump felt tight and could not turn, i then let the air out and it turned freely again.
I decided to buy new non return valve because the rubber on the old one felt hard and that defnitly was the problem, i then put the new one on and it is doing the same thing, the compressor runs a bit longer about half full and the motor starts labouring again, it only runs when i let the air out.
What could the problem be, can you please help.
Bill says...
It was a good call to check the non-return valve in the line to the tank. If that was preventing access of the compressed air to the tank, then that might have been the cause of your problem.
Normally the check valve fails by leaking, and when the compressor stops and unloads, that leaking check valve lets all the air out of the tank as well as that trapped over the piston.
If it's not the check valve, then all it can be is a problem with the power train.
Your motor may be failing and can't overcome the increasing load as the tank fills, or the compressor head itself has a mechanical issue that bogs the motor down when the pressure builds.
If it is a lubed compressor, make sure the oil sump is full, as low oil could result in friction caused heat and increasing load on the mechanical parts of the compressor as they heat up.
Good luck.
Bill
