Compressor runs, will not build pressure

by Steve
( Jacksonville, Florida)

I've picked up a free Craftsman 5 horse 12 gallon oilfree compressor that will run, but will not build pressure. After taking the head off, and cleaning the wasp nests out of the intake(will need to get a new air filter), then reinstalling the head, I ran the compressor again. Still no pressure build-up. I di notice a brass fitting on the opposite side of the head from the intake that air was escaping from. I re-read your compressor book and couldn't find mention of this part(I think its got to be a check valve of some sort). It seems to me that it's exhausting air at the same rate that flowing in the intake. Could this be the problem with my compressor not building pressure or is there something I'm overlooking?
Thank you Steve

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Bill says...

Steve, wasps are fun? Listen, look at your compressor, and spot the line that runs from the compressor head into the check valve and the tank.

Don't see it?

I'm thinking this line is missing, and the air that you are compressing is flowing, appropriately, out the fitting to the line to the tank, but since there's no line, it's simply going back to atmosphere. Just a guess.

Send in a photo if you want me to look at it.

If there is a line from the head to the tank, then I have no idea what this fitting you refer to is. A picture might help.

Also, check out this page for reasons why a compressor won't build pressure. .

Did you find the book helpful? Any constructive criticism?

Cheers,

Bill