I have a 20 gallon devilbliss air compressor that will on build 70 psi of air. Motor continues to run but will not let anymore air into tank? Pressure switch already been replaced but to no avail.Help

SOURCE: 1 HP 3 Gallon Air Compressor does not build up pressure.

it sounds like the regulator is out of whack turning down increases air pressure. make sure there is no leaks

SOURCE: porter cable 3hp air compressor

Hi,
Check to see if the switch will kick in if the pressure is released from the hose going to activate it...if so then the problem is the air being trapped between a check valve and the switch in the hose...
I think that is your problem...
There should be a way for the air pressure to change and represent the tank air pressure accurately....
The different compressors all have different ways of checking the air and then allowing it to release as the the tank pressure decreases..

There is a small hole there somewhere that is clogged with dirt and or oil...find that and clean it and you are in business again...

heatman101

SOURCE: hello, I have a Craftsman

replace the check valve. $8:00 solution

Donald DCruz

• 17130 Answers
• Posted on Mar 15, 2012

SOURCE: I have a 21 gallon 4hp peak motor Central Pneumatic oil lubricated Model 47065 air compressor and it will not go to over 20 psi and it will just keep running

Possible that there is leak on the system or the piston/rings/cylinder has worn out.Also check for oil within the unit. Check the compression of the cycle and if this is too low it means that there is wear and tear and will require a overhauling and reset.