Help with a vintage Quincy single cylinder pump

by Carlos Bernardo
(Santa Rosa, Ca. /95403)

I have been using a vintage Quincy single cyl, single stage apparently a '50s model as it looks identical to a picture on your site I.D ed as an A 4-7


I have it installed on a 60 gal. horizontal tank and powered by a reconditioned dual voltage Leeson electric motor, currently wired for A/C single phase 220V service. Has given trouble free service, equipped with line Pressure gauge, Combo - water filter/trap & manual line pressure regulating device, plus safety pop off valve and condensate drain valve at bottom of the tank.

However recently it runs longer than normal, but is not pumping?

It normally will pump to a preset 150 PSI in around 10 minutes of operation. Now it won't do more than around 10 PSI??

Is there a rubber diaphragm used in this pump?

This is only my first attempt to trouble shoot, but need some info.

I was going to contact a Repair Company in Dixon, but found your site, so am giving ya' all, a shot at normal failure, which as I am told is seldom a problem? But, after 60 plus yrs. of service something's bound to have failed!

Any general advice would be appreciated. Sorry no pictures, no cell phone for this old man...and I haven't had time to set up my PC for that purpose, but am working on it???

Thanx in advance:
Submitted by Carlos Bernardo
Ex Navy Seabee
Retired Fleet Maintenance mechanic

I'm 82 and still wrench on my own stuff!

Comments for Help with a vintage Quincy single cylinder pump

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Nov 03, 2016
Help with a vintage Quincy
by: Bill

Mr. Bernardo... 82 years and still wrenching. Good on you!

I don't know if your vintage Quincy has rubber diaphragm, but I would doubt it.

If you can wander over to the troubleshooting section on this site and have a look at the pages about why compressors run and don't build pressure, there will be some tips there.

Offhand, I'd guess your pump may have a gasket leak or a valve problem.

If you are ever able to get photos of your pump, please start a new post on this forum, and ask in the comment section that the pictures be moved to here: (Help with a vintage Quincy single cylinder pump).

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