Craftsman compressor motor runs and it does not build up pressure

it will run but does not build up pressure and will not cut off with out me manualy turning it off

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This is a common problem, it seems, for many DIY type air compressors.

Unplug it and dump any air pressure in the tank to zero PSI. Close the tank drain. Unscrew the intake filter (if possible). Plug compressor in. Can you feel air being pulled into the compressor through the port? Do you feel air being blown out too?

Give me an answer to this by posting here, and we'll carry on. Or, you can look under the Troubleshooting button for your symptoms, and many of the tips will be on those pages too.

Cheers,

Bill

Comments for Craftsman compressor motor runs and it does not build up pressure

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Apr 02, 2013
same problem
by: Anonymous

Same problem here checked what you said! air in air out but won't send air to tank!
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If by air in and air out you mean that air is coming in and out of the intake valve port, that normally means that the intake valve is pooched.

You need to tear down the pump, and replace any gasket layers along with the valve plate, I suspect.

B.

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Craftsman 921.153101 Question About Gaskets

by Rick
(College Place, WA)

Craftsman 921.153101 3-gallon, 1.5HP, Oiler

Bill - this is a great site! Thanks for educating us.

After reading the Q&A on why compressors won't build pressure past a certain point, I was able to figure out that I have a head gasket problem. Before I get a new one, I have a few questions:

1. Should I go ahead and replace the upper cylinder gasket along with the head gasket? They are the same age and material, so I was just thinking that I might as well change them both at the same time.

2. Looking in my compressor manual, I noticed that there is another gasket shown in the diagram and on the parts list, called the Valve Plate Gasket. However, when I pulled the head off the cylinder to check the reeds, I discovered that there was no existing valve plate gasket. This unit is only a few years old and I have never had it apart before. I also noticed that a few others had posted questions with pictures of the exact same model, and they also show no gasket. So, my question is, should I order and install this gasket if it is available? It seems odd that they would omit this gasket - which sits between the two valve plates - in the first place. What's with that???

3. Should I replace the reeds at the same time?

Thanks again!

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Bill says...

Thanks for your kind comment.

Re: 1) I would

Re: 2) I wouldn't

Re: 3) Maybe, depending on their condition - brittle etc.

Sometimes compressor designs change, and although it may be axiomatic that the manual would be changed too, that could drop through the cracks. If the manufacturer left the gasket off, and the compressor worked fine before, I wouldn't add one now.

Cheers,

Bill


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