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Question About Craftsman Air Compressor 921.166390
pressure will not build up...

With the compressor empty, compressor does pump air pressure up to check valve. Even with check valve spring and seat removed, the pressure does not build up in tank. Compressor is relatively new. Craftman 7 gal., 1 HP, Oil lubricated, 120vac

Asked by Lee Rivera on 08/22/2010 9  Answers

ManualsOnline posted an answer 14 years, 1 month ago

The ManualsOnline team has found the manual for this product! We hope it helps solve your problem. Get the Manual Here

Art posted an answer 13 years, 4 months ago

2 Will not build pressure. Appeared to be out of oil. Filled with oil, and when turned on, it sprayed oil out of the pin hole in the filler cap. What gives?
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Jim posted an answer 14 years, 1 month ago

1 Are you sure the condensation drain valve at the bottom of the tank is not open...? Sounds like something is open somewhere in the tank... Jim
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Lee Rivera posted an answer 14 years, 1 month ago

0 Thank you for ur response. Yes the condensation valve was closed. I have even removed the tubing from the check valve to the pressure switch and blocked the connection. In otherwords, there is only one path the air has to go to , and that is straight to the tank. Perhaps, being impatient, I did not allow enough time for the air to built up. Nevertheless, I did not noticed even the slighted movement on the gauge.
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Jim posted an answer 14 years, 1 month ago

0 Hmmmm... you got me on that one then... is it possible the gauge is bad...? Jim
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Lee Rivera posted an answer 14 years, 1 month ago

0 Thanks again, it has me baffled too. It should be very straight forward. Thanks again for your input.
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Rafael Hernandez posted an answer 14 years, 1 month ago

0 Compressor stopped totally. Started running then stop; rebuild pressure then run a few seconds and cuts off this continues off and on. and finally stopped.
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William posted an answer 12 years, 11 months ago

0
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Jim posted an answer 12 years, 11 months ago

0 Wow, that's a lot of crankcase pressure blowing past the pistons if it blowing oil out the breather cap...! That could explain why no air pressure going to tank, if the pistons and/or rings are compromised and letting air enter the crankcase instead out of the head valves. However, it could be a head gasket too...? Don't know, but it sounds like time for a tear down to find out why...?
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