Craftsman Model 921.153101 - 3 gal. Oil lubricated, 1 HP

by Pete Johnson
(Jax Beach, FL)

Craftsman Model 921.153101 - 3 gal. Oil lubricated, 1 HP

I have T/S unit thoroughly (I think) - tank pressurizes, but will not d/c thru hose. Safety valve on side of pressure switch releases air, as well as the bleed valve on bottom of tank.
I have used 2 hoses with different end fittings (quick release), air gun and tire inflator tools, and even inserted the air gun directly into pressure switch outlet port, with no hose. Air does not come out. This tells me the pressure switch must be blocked.....
Please share your thoughts before I contact Sears and spend money.
Unit was purchased in 12/13 and extended warranty (yeah, I bought it) expired last year......
Has only had light to moderate use.......

Thank you!


Comments for Craftsman Model 921.153101 - 3 gal. Oil lubricated, 1 HP

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Aug 27, 2017
Air flow problem
by: Bill

Good that removing the regulator allowed full flow Pete.

If you don't need that high a pressure though, a working regulator will reduce air use and energy cost.

That nasty looking calcium-like stuff in the old regulator came from your compressor tank. Is the air intake on the compressor somewhere that it could be ingesting this dust? If so, venting fresh air to the intake should help resolve that.

You are most welcome. We are all to have been of help.

Aug 26, 2017
921.153101 no air
by: Doug in

Just to elaborate, you have two gauges. One is tank pressure, and the other is outlet pressure. Both should show pressure.

If the one by the the regulator is not showing pressure, can you adjust the regulator so it does?

If it is showing pressure, then maybe the coupler is bad.

You could drain all the air in the tank, remove the coupler, and turn it on - do you get air now? Then buy a new coupler.

Else, what Bill said.

Aug 26, 2017
Reply to request for assistance
by: Pete Johnson


Thank you for your thoughts and quick reply!
Learned a lot about the compressor and connectors.
Yesterday I disconnected and trashed the Regulator due to a build-up of nasty looking calcium white stuff inside the ports. I did not need this piece - I just wanted straight self-regulated air pressure, so discarded it.
Connecting directly into the Pressure Switch was all I needed ....
And once I determined that firmly seating the male quick connector into the female I was good to go.
A few times of connecting / disconnecting made the process easier - the parts fit better....
No parts ordering needed now - things seem to be working fine. I am happy!
Once again, thank you!


Aug 26, 2017

by: Bill

Does this "inserted the air gun directly into pressure switch outlet port" mean that you inserted the connector into a coupler?

If so, was the coupler downstream of the pressure switch?

Was it also downstream of the pressure regulator?

If so, I would surmise that your air regulator has failed.

Please advise.

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