Compressor won't pressurize—tank "check valve" issue?

by James
(San Jose, CA)

1972 Montgomery Wards Air Compressor

1972 Montgomery Wards Air Compressor

My compressor is a Montgomery Wards brand 220v/1.5 hp 20 gallon model, with a Franklin Electric motor, a two-cylinder compressor, and a Kargard Industries tank. The date code on both the tank and the motor are 1972.

It seems my compressor has the same symptoms as the previous poster—it will not pressurize the tank above ~40 PSI. When the compressor is first turned on with the tank unpressurized, I can feel the cylinders sucking in air as they should; but as the pressure builds, more and more air is pushed right back out the intake valve. As with the previous poster, I disassembled the heads on my compressor to check the valves. They're just flat reed valves, and appeared to be in fine condition, just a little dirty. I cleaned the valves, head, and ports copiously, replaced the gaskets with new ones, and reassembled. But this did not solve the problem. Neither does changing or even removing the air filter.

Bill, you mentioned something about a "check valve going into the tank" in regards to the previous poster's problem. While his problem turned out to be a head gasket issue, it doesn't appear that mine is, so I would like to know more about this check valve. What is its purpose, where exactly is it located, and how do I test it?

Thanks for the help!

-James





Bill answers...

Hello James. Thanks for visiting, writing in, and including a photo. It sometimes makes answering so much easier.

If you look at your photo, see where the air line from the piston head turns and runs down to the tank on the left? Usually, the device that connects that air line to the tank opening is a check valve.

It's purpose is to keep the air in the tank as the piston compresses it. The higher pressure air flows down the line, through the check valve, and into the tank.

If this check valve isn't seating properly, or has failed completely, then air can't stay in the tank as it's higher pressure in the tank than the line is when the piston is in the "suction" cycle.

This may be an issue for you. Best to make sure the tank is empty, compressor is unplugged, and the disassemble the fittings at the tank, and examine the check valve. It should seal the air in one direction.

Reassemble after cleaning (if needed) and see if this makes any difference, OK?

Cheers,

Bill




Comments for
Compressor won't pressurize—tank "check valve" issue?

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Jan 09, 2012
 Looks like a Champion pump
by: Smithereens

Sorry to barge in here, but I saw a lot of posters asking about the pump on the Ward's unit. That looks to me like a Champion pump, and parts are still available for those. They were used on a variety of brands (Speed Aire, for instance), and they made a million of them, much like the cast iron Campbell Hausfelds. Check with Grainger or Champion - I think you will find the parts.
- Mark
Oct 30, 2011
 my 1972 speedair compressor,like pictured
by: john mc gonagle

Hi Bill, my compressor looks just like the 1972 Wards,picture you have. Mine says made by Kargard industries. My problem is that one piston blows air outward,but the other one works normally. What is wrong?,where do I get parts,and how do I fix it? Thank you, Bill,it sure is nice to see somone who knows these things. John Mc Gonagle

_________________

Not sure what you mean by blowing air outward. Are you saying that the intake port is blowing air out instead of pulling it in? If so, that's a valve problem. Good luck on getting parts.
Sep 01, 2011
 almost free
by: Fritz Silberstein

Have a compressor like the Wards pictured here with a Doer 230 V motor. Can it be rewired? If not the thing is yours for $50 in Eureka, CA at (707)444-3228. Don't want to mess with putting in 230 in my garage.
Aug 01, 2011
 I have a 1974 wards compressor
by: ron

Where are we getting parts for these compessors?
Apr 08, 2011
 Same Pump, Different Tank
by: jwellison67@yahoo.com

I have an identical pump to the one pictured, that was found in an old building that we won at an auction, but it's on a much smaller (portable) tank and runs on 110V. My problem is that one of the pistons has been removed, and it is missing the rings. Everything else is there... except the rings. Does anyone have any ideas on where to find a set that fits?
May 20, 2010
 Similar air compressor
by: Anonymous

I have an air compressor that is a 1974 that appears to have the same pump that yours has. However it has a newer motor on it. I was wondering if you could tell me the pump rpm's or the pulley sizes and the motor rpm's. Also I didn't know if there was any information on the pump itself. Any information you could give me would be great.

Thanks
May 07, 2010
 added info check valve
by: Larry NM

If I am not mistaken that is a check/unloading valve. I have the next smaller version of that compressor shown in the picture. The unloading part quit working and I had it worked on. He installed a check valve and the compressor wont start under pressure. I am trying to order on at this time.

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