921-166400 won't build pressure

by Charles
(Shelbyville, Il. USA)

Craftsman 921.166400

Craftsman 921.166400

Craftsman 12 gallon 1 HP Oil Lubricated Model # 921-166400 runs but no pressure build up.

I have scoured your web sight and have done everything suggested.

If it is a problem with the reeds, how do you tell if the reeds are bad? They are two strips of metal and look in good condition.

Seems air is going in and out as it should. If the pressure is as it should be can you hold your finger over the open air line at say the check valve?

Any place I break the line open, I can easily put my finger over the line opening and restrict the air flow.

Comments for 921-166400 won't build pressure

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May 24, 2016
Solved problem
by: Anonymous

Replaced gaskets problem solved. Thanks

Mar 20, 2016
Craftsman 921.166400 no pressure
by: Bill

If you push really hard on a line from the pump you may be able to block the air escaping, but only for a bit, and you don't want to do that anyway.

When you did block the line a bit, did you hear any slowdown or lugging on the motor?

If you feel the valve fingers are fine, and you've checked everything else referred to in the troubleshooting pages on my site, my guess would be the pump seals are worn.

When the pump is running, can you feel air escaping out of the oil fill tube cap?

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