Changing compressor on P38

porschedrvr said:

Hello....new to this forum. I have a compressor issue and have run out of ideas. It runs every 15 seconds after vblock rebuild. (new bags,compressor.? ck'd all 0-rings and seals ...no bubbles. replaced pressure switch with new one for atlantic british....HELP????

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I have exactly the same problem! trhank god im not the only one!!

It seems to be fairly normal. Mine does too. Got a pressure gauge on my tank feed. Once it drops much below 135psi the compressor starts running again. RAVE says it should be 120psi. Tried new pressure switch. No difference. I've given up worrying about it!

Grrrrrr said:

It seems to be fairly normal. Mine does too. Got a pressure gauge on my tank feed. Once it drops much below 135psi the compressor starts running again. RAVE says it should be 120psi. Tried new pressure switch. No difference. I've given up worrying about it!

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Been through this before. Compressor should start at 120 psi + or - 7 psi. Should stop at 140 psi + or - 7 psi. So could run with a 34 psi differential if it starts at the lower end of 113 psi and stops at the higher end of 147 psi. Or as little as a 6 psi differential if it starts at 127 psi and stops at 133 psi. Or any combination in between. So it is a bit hit and miss depending how good the pressure switch is.

But if its running to much is it not gonna kill the compressor?

gazzab79 said:

But if its running to much is it not gonna kill the compressor?

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If it's not making height changes and there are no leaks it should not need to run that often. If it has an high differential it runs longer from low to high. If it has a low differential it runs in short bursts. As broad as it's long really.