Central Pneumatic 42321 Keeps running

by Ken

My compressor keeps running till the manual pressure release value engages at 120 psi.

I have looked on line and the DIY people say to take off the cover on the Auto shut off but mine is old and there is no way to open.

Does anyone have a way to adjust the auto shut off on the 2 horse machine?

Ken Gunn

Comments for Central Pneumatic 42321 Keeps running

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Jun 22, 2015
pressure switch / PRV
by: Doug in s.d.ca

Is there not a screw near the bottom of the pressure switch/unloader on the pump side? Takes a long (not stubby) screwdriver to reach.

Probaly a LeFoo from the look of it.

BTW, your compressor is supposed to cut-out at 115 (MAX) and cut-in at 80.

So, the good news is your PRV is working correctly.

I found manual at http://www.manualslib.com/manual/256682/Central-Pneumatic-42321.html#manual
in case you don't have one.

Jun 22, 2015
Pressure switch
by: Bill

Ken, though you have a problem removing the cover of your compressor pressure switch, based on the symptoms I suspect that it is your pressure switch that has failed.

No OEM parts are available for the 42321 that I can see, though many pressure switches are not really OEM, but made for that compressor manufacturer and many others by an outside company.

In other words, if you remove your pressure switch (power off - tank totally empty first) take it with you to the compressor outlet to find a replacement.

See the page on this site about what you need to know about replacing your pressure switch to help you figure out which new one you need.


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