Central Pneumatic Model 94667 wont stop running

by Curt
(Oldtown, Idaho)

My compressor wont stop running and continues to build pressure until it pops its release valve. Wont restart until totally out of air.

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Curt, your compressor symptoms point, at least as far as I am concerned, to a pressure switch issue.

The pressure switch controls both the power to the compressor motor, and also toggles the unloader valve.

It sounds like your unloader valve isn't dumping air either, and since the power continues to flow to the compressor motor to the point where the PRV lets go, that shouts "time for a new pressure switch" to me.

Cheers,

Bill

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Multiple problems on 94667?

Rob,

Does anyone have the manual for model 94667? I wondering if there is a parts list and schematic in manual.

I took the pressure switch/power switch assembly apart to check the rubber gasket. The assembly popped apart and I trying to figure out how to put it back together.

As other folks have posted on your site, I have the problems with the compressor not building pressure over 40 psi. Air is blowing from the muffler style filter and from the smaller black filter or vent above the oil reservoir.

Any help would be greatly appreciated.

John
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John, your request for a manual is posted. Unfortunately, I have not been able to obtain a copy of it to include on this site for others to download.

As to your compressor symptoms, the leaking air intake filter suggests your intake valve is pooched. I would suspect the pressure valve, typically located on the same plate, to be suspect as well.

As far as air blowing out of the oil fill cap vent, that suggests that your piston rings have worn to the point where compressed air is bypassing them into, and pressurizing, the sump. That pressure is venting out the oil fill cap.

It sounds like it is time for a complete rebuild of the pump, John.

Cheers,

Bill



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At the moment I can't get the pressure switch back together

by richard
(cleveland,tn)

My harbor freight 94667 changed sound while building up around 85- 90 and got no higher still running. It held pressure it had over weekend, till harbor returned my call, He suggested
take apart pressure switch saying it could be leaking, while trying to build up.

But i tried several other things first, cause i just didn,t think that was problem. i took the head off every thing looked ok, piston go up and down by hand and motor walls look smooth. no bubbles in oil, as he suggested if rings were bad.

took lines loose and found some white
corosion stuff at the little line that goes to pressure switch, thought that was problem cleaned blowed thru, no.

also cleaned the same joint where the spring and rubber seals at top of tank, which is what clerk at store said might be the trouble, ( that was what i did first).

took big line lose at that joint, have pressure coming out and suction in at intake, part of time seems to blow out intake which means rings ??????,

but as last resort I tried first thing he told me over phone, take apart pressure switch, I did
and could seen nothing wrong but can,t get it back together that stiff spring and loose parts, Hope this makes sense to you .

Thanks for any feedback. reed valve looked ok
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Richard, wish you'd read some of the pages on this website before you starting cannablizing your pressure switch.

From what you have written, I believe the Model 94667 compressor problem you are having is an intake valve failure. You say "part of time seems to blow out intake which means rings " which means that as the piston cycles, instead of air being driven into the tank, it's cycling in and out of the intake valve. That valve should be shut when the piston is on the compression stroke.

As to the pressure switch, nope, I don't know how to take them apart or put them back together. There is no value to me in spending multi-hours tryring to fix an compressor component that costs $30 or so.

If it were me, I'd chalk the pressure switch experiment up to experience, buy a new one, but after I had fixed the valve issue.

Cheers,

Bill



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94667 check valve leaks?

by Tilmon Strickland
(ADA OKlahoma)

Central pneumatic Air compressor #94667 ,21 Gallon compressor.

There is a brass check valve on the FENWAI FW-10 pressure control valve that has started leaking air ,its the valve that turns the compressor on and off AUTOMATICALLY,

I am told by Harbor Freight that this part is not available or obsolete, then it is suggested that the pressure switch off of model 95386 may work on my model; however, since the two models are not directly cross referenced against each other, they cannot guarantee a direct fit. In other words purchase at your own risk.

My best suggestion is to buy minimum (2) two year extended warranty cause this "BRAND" Chicago pneumatic Air compressors are only built to last approximately (1.5) one and a half years from date of purchase.

This is my second compressor of this band and it lasted about the same as the first . I thought the first was just coincidence but now the second one having problems as well and then reading other online complaints I think this Brand is "PLAGUED"
No More for me.

BUY AT YOUR OWN RISK!!!!
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Hi Tilmon. Two things.

Before doing anything else, dump all the air with the compressor off, remove, clean, and replace the tank check valve and see if this resolves the issue.

Did that help? Post a comment here, please.

Cheers,

Bill

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Apr 02, 2012
CORRECTION !!
by: Tilmon Strickland

It has been brought to my attention that I made a mistake concerning the Brand Name of the Air Compressor , It is "CENTRAL PNEUMATIC" Not Chicago Pneumatic.
Sorry About that.

Apr 02, 2012
check valve continue
by: pcbeachrat

Sory I forgot to add that just about any switch will fit that pump that has the fittings set up the same way..even tractor supply sells one that will,as well as most places that sell the switches.As long as the switch is set to the proper pressure for cut on/cut off and the voltage is the same...you are okay...the switch is not that crucial on finding the EXCACT type that is on there now...No need to look for the same excact one

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As long as everything that is connected to the old switch is still connect and working in the new, the unloader valve interface for example, as you point out.


Apr 02, 2012
CHECK VALVE
by: pcbeachrat

The item you are talking about is not a check valve,it is called a "unloader valve" that is on the switch.The check valve screws directly into the tank which on an upright is right at the very top of the tank.The small valve that is on the switch itself,and usually routes with a small 1/4 inch tube either plastic or metal is the unloader valve which when operating right shuts the compressor off once filled to the set pressure,and then releases a small pfffttt right at the end fter it stops.This releases some pressure on the tank so it wil be able to start up again without flooding the motor down and not allowing it to turn.

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