# Compressor repair help



## RetiredUBClocal (Jul 13, 2012)

Hi Guys, I need your help. My father-in-law bought a Husky compressor about 7 years ago and I have been using it to fill tires but it doesn't recycle. I've had to turn it off, wait, and turn it back on to get it it cycle on and fill again. It's supposed to go to 150 psi but when I tried to use it yesterday, it would only go up to 50 psi.

I'm planning to put an addition on my house and I'd like to be able to use this as power an air nailer if I can fix it. Can you help a retired carpenter out?

Thank you, Jim


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## DexterII (Jul 14, 2010)

Pump it up to full pressure, remove the pressure switch cover, and watch the contacts while bleeding the pressure down. At some point, probably in the 120 to 130 psi range, the contacts in the pressure switch should close. If they are not closing, I would suspect a bad pressure switch, a leak between the tank and the pressure switch, or a kink in that line. If they are closing, the contacts may be bad in the pressure switch, or, you may have a bad check valve, which you may be able to take apart and clean, or may need to replace.


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## joecaption (Nov 30, 2011)

Also check the line from the tank to the pressure switch. It's it's kinked or leaking it can cause this to happen.
Another common problum is the funky way the line fits where it goes into the head of the compressor.
Most use a cheap rubber washer that rots out over time.
Good luck trying to find parts for it.
Campbell Hosfield or DeVibiss made a lot of there compressors. There also the ones used on Porta Cable branded compressors.


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## CopperClad (Jun 22, 2012)

Is this an electric or gas powered compressor?


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## RetiredUBClocal (Jul 13, 2012)

This is an electric compressor. I know that this only a homeowner model but if I can get it to work it will really make my life easier with my additions. It has really just sat around for the past five years. It looks like it should be easy to fix, there aren't too many parts. I'll try changing the pressure switch and check valve.

Here's my house with the garage addition and the sunroom addition. It's great to be retired after 40 years of Heavy Construction in NYC


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## RetiredUBClocal (Jul 13, 2012)

I'm going to replace the pressure switch. Do I need to get the same one?

How do I know which on to get?


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## DexterII (Jul 14, 2010)

You need to know the pressure at which the air compressor will turn off, the pressure at which it will turn on, the pipe thread size, whether they are male or female threads, and whether or not you need an unloader port, which would be where a separate line may or not connect to the side of your switch. I assume that our pressure switch does have an unloader port, but, if not, you can use either style, and just leave the unloader port on the new pressure switch unattached to anything. Your best bet with these smaller compressors though is to try to find the exact replacement, because the space is generally pretty type, and, although maybe not that common, I have seen some of the lower end ones with unique thread sizes.


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## Thurman (Feb 9, 2009)

O.K., here's what we know: " It's supposed to go to 150 psi but when I tried to use it yesterday, it would only go up to 50 psi." Let's rule out the pressure switch for right now. He's only getting 50 psi at this point, but--he doesn't say if the unit is cutting off at 50 psi or not. Let's say: not, that the unit keeps running but stops pressurizing at 50 psi. Look at the actual compressor unit and follow _probably _a copper tube that goes into the tank. At a point just before the tubing gets to the tank there should be a hex shaped nut which looks like the tubing is attached to something before the tank--it should be. Between the tubing and the tank is the "check valve". This allows compressed air to be pushed into the tank, but will not allow the compressed air to come back into the tubing. This is how the unit compresses air into the tank. Also--when the unit is running the line from the compressor to the tank _probably_ feels very hot. This is wrong, it should be quite warm but not _very hot. _IF it feels very hot then this is a true indicator that the check valve is not working. The check valve is easy to remove and check (pardon the pun). Remove the line going into the check valve, remove the check valve assembly from the tank. Try to blow through the check valve in the direction the system was plumbed. Then try to blow through the check valve the other way. IF you can blow, at all, through both ways--bad check valve. Sometimes, a few times, you can clean the check valve with something like WD-40 and get the grime out of it that makes it stick open. I have actually used a carb cleaner to clean some bad ones. Now--IF the check valve appears to be working fine, then the pressure switch would be the next thing I would look into. With the unit having NO air pressure at all, make sure the unit is unplugged from electricity, remove the pressure switch cover--STOP. With the cover off plug the unit back in BUT--do not touch anything within the pressure switch. Start the compressor and just watch the switch to see if anything moves when the unit gets to the 50 psi point. IF there is no movement, the compressor still runs at the 50 psi point--bad check valve. IF there is movement within the pressure switch at the 50 psi point and the unit stops---bad pressure switch. A lot of pressure switches for small units like this one have a "cut-in (start)" setting at between 80psi and 90 psi with a "cut-out (stop)" setting of around 125 psi--150 psi, depending on the unit/manufacturer. IF your's is cutting out at 50 psi, the diaphragm probably has a hole in it--new switch time. Hopefully this will help---IF NOT, ship it to me for repair


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## RetiredUBClocal (Jul 13, 2012)

The compressor cuts off. Yesterday it went to 75 psi then cut off. After I drain the pressure all the way down, I have to shut if off, wait, turn in one again to get it to pump back up. Again yesterday it went to 75.

I found the parts Mastertoolrepair, listed for a Campbell Hausfeld. Today I will check the check valve and see what I find out.


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## RetiredUBClocal (Jul 13, 2012)

OK, I checked the check valve by blowing and it only goes one way. I put it back together and started it up. I saw where the contacts on the pressure switch stay closed when it's running and opened when I turn the switch to off. When it pumps to 50 psi, it cuts off but the contacts stay closed and I hear air blow off. I turned it off and waited, turned it back on and it got to 80, next time 90, 100. It would shut off and air would blow out but the contacts never opened. The hose to the check valve is hot but not as hot as the fins on the motor. I'm willing to order a check valve and a pressure switch, but is there a chance that it is the pump?


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## DexterII (Jul 14, 2010)

First of all, when it shuts off, does it blow air for a second or two, or does it continue to bleed down? If momentary, your unloader is working, so that is good, but if it continues to bleed down, your unloader is not working or you have a leak someplace. After that, given that it is shutting off with the points still closed, there is a small possibility that the contacts in the pressure switch are bad, but I would lean more toward the check valve, as Thurman explained, which in turn is causing the thermal protection in the motor to shut it down. Frankly though, the second thing that I would do, after confirming that the unloader is functioning properly, and that you have no other leaks, is to replace the gauge, just to make sure that the picture you have is real. Gauges are readily available, and inexpensive, so, again, I would do that, and then post what you find.


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## RetiredUBClocal (Jul 13, 2012)

When the motor stops there is a blow off, no bleeding down. The copper hose to the check valve gets very hot. I'm going to start by replacing the check valve. Is this a common part that I can get anywhere or do I need to order the exact one?


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## DexterII (Jul 14, 2010)

Its' physical attributes are all that you really need to worry about; the proper threads on each side, its' length, depending on how much room you have to play with, without having to change the lines as well, and whether it has a port for the unloader. If yours does not have an unloader port, and you find one that does have a port, but is otherwise the same, you can just plug it. I would check the local air compressor shops in your area, but would not be surprised if it is somewhat proprietary, and that you end up having to order it online.


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## RetiredUBClocal (Jul 13, 2012)

Well guys, I replaced the check valve and the pressure switch and I still have the same problem. The compressor gets up to 50 psi and cuts out, the copper hose to the check valve gets hot and it won't turn back on until I switch it off and wait a minute. Then I pumps up to 50 psi again.

What else can it be?


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## DexterII (Jul 14, 2010)

RetiredUBClocal said:


> The compressor gets up to 50 psi and cuts out, ...and it won't turn back on until I switch it off and wait a minute. Then I pumps up to 50 psi again.


It pumps up to 50 psi, shuts off, you switch it off, you wait a minute, you switch it back on, and it pumps up to 50 psi again. Between the first and second time that you start it, where did the pressure go? I think that you said before that it is not leaking, but, unless you are intentionally bleeding it off, it sounds to me like it is leaking.


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## RetiredUBClocal (Jul 13, 2012)

No, pressure jsut sits there. I can get it to pump up about 10 psi at a time if I keep shutting it off and turning it on.


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## DexterII (Jul 14, 2010)

Okay, this late breaking information changes things a bit. If it only runs long enough to increase the pressure 10 psi at a time, I would suspect that thermal overload on the motor is kicking out. If you are running this on an extension cord, unplug it, plug it directly into a wall receptacle, and try it that way. If the results are the same, although perhaps not quite as likely, if you are running this in a garage, shed, or other building separate from where your main panel is located, take it to that building and try it, again, without an extension cord.


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## RetiredUBClocal (Jul 13, 2012)

Darn, I thought you had it. I ran it from a 20 amp outlet on my generator and it did the same thing but it went to 75 psi to start. I do have more info though. When it kicks out, it releases a small amount of air from the check valve for a short time then holds pressure. I put the old check valve back in and it does the same thing.

Help!


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## RetiredUBClocal (Jul 13, 2012)

One more thing; the pressure switch never opens.


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## DexterII (Jul 14, 2010)

The little bit of air that blows off when it shuts off is normal; that is the unloader, releasing pressure in the discharge line between the head and tank, which it is supposed to do. Running an air compressor on a generator is never a good idea, in my opinion, due to the initial current draw at startup, which can easily double the current draw, or more. I am out of ideas, other than the fact that I still suspect that the motor is kicking out due to an inadequate power supply, the pump is siezing, or the motor itself is bad. The fact that the contacts in your pressure switch are not moving pretty much confirms that fact, in my opinion. If your house has older wiring, maybe haul it to a buddy's, and see how it works there. Otherwise, good luck. Maybe someone else will have some other ideas.


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## Idmason60 (May 17, 2010)

Could be the reed flapper valves in the compressor head. I think both 
oil and oil less compressors have them. They are thin strips of metal that act as valve so compression can happen. If broken,rusted,cracked they can keep the compressor from coming up to full pressure. Most compressors have 2 to 4 of these.. They aren't expensive but a new head gasket will need to be made or purchased if replaced or inspected. 



Larry


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## RetiredUBClocal (Jul 13, 2012)

It doesn't look like they sell the flapper valves. My next option is to buy a complete motor and pump unit for $196. That seems too much. I think I should cut my losses and send back the pressure switch, then go buy a new compressor. Do you agree?


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