Speedaire pressure switch issue

by John Hein
(Dublin, Ohio)

I have a Speedaire model 3z419, which is about 35 years old. The pressure switch is not working correctly.

The motor runs the pump until the safety valve blows.

I called Grainger and they did send me a copy of the parts list, but the pressure switch is no longer available as a repair part.

Grainger did offer to try and "source the part", but that requires an account with Grainger. They are really a wholesale house and don't accommodate retail business. If you have an account, or know someone that does and can get permission to use their account number, you can still pay cash or by credit.