Compressor pressure switch issue

[jduncan459]

I just (today) got my compressor hooked back up after 4 years or so of being in storage. It's a Husky from 2001, 6.5 horse 60 gal.

I have a leak around the pressure switch I cannot find. I have taken it off and sealed every port, guage and plug with teflon pipe sealant. But somehow it is leaking when it's running. When I turn off the compressor, it doesn't leak. This is driving me crazy.

I won't get up to 135 psi, only about 80 and that is when I turn it off because I know it's not going to make it. I have left it on for 20 minutes and it won't. No leaks anywhere else. THere must be something I am missing.

Help!!

 

[94yj]

sounds like the pressure went out on you and it is fairly common

 

[Lightfoot]

I recently repaired one for a friend of mine. it leaked only when running. one of the tips of the three reed valves in the head had chipped off and was allowing pressure to backfeed to the switch while it was running. his would only get to about 65 lbs no matter how long i ran it. Pull the head and check them first.
replacing them is very easy once you get to them.


www.mastertoolrepair.com
very nice folks to deal with for compressor parts. I looked-they do carry parts for Husky. Call them, tell them what the compressor is doing, likely they will tell you over the phone what the problem is and provide you the part number you need. I had my parts in two days

 

[jduncan459]

Ok, that makes some sense. Leaking only when running was not making sense before!

 

[jduncan459]

Actually, that isn't it either. I removed the check valve from the top of the tank (where the output from the compressor head connects to) and the valve seems ok. The pressure is actually coming from the thin plastic tube that connects to the compressor side of that valve. This connects to the pressure switch and is supposed to relieve the pressure on the head after the switch turns off. But it just leaks through that hose. Maybe this is normal.



Edit: Can't be normal but I don't see what is supposed to stop the line from venting enough pressure to slow or stop the thing from reaching 125psi. There's no valve there so the full pressure vents though that teflon line. It ***** that there is little or no info on this compressor due to it's being 10 years old.

 

[Skin]

sounds like a new switch to me. The little pin is probably stuck open. If its the kind of switch i'm thinking of its suppose to pop out when it hits the cut-off pressure then retract.

 

[Lightfoot]

John,
If that check valve going to your tank was bad, it would continue leaking even after the compressor shut off, until the tank was empty. The reed valves (different from check valve) are inside the head and you have to pull the head off the compressor unit to get to them. Are you saying you already had the head off and checked the reed valves? If i read your post wrong, i apologize-just trying to help.

 

[jduncan459]

I see what you're saying about the reed valves, but the pressure only comes out of that hose when it's running. There would be no difference in operation or the leak whether the reed switches were allowing bleedback or not as the path is the same.

Nothing leaks "out" of the switch when it's running. The full pressure is coming from the line running to the unloader valve. I guess the unloader valve is supposed to accept that pressure but it doesn't.

My head is spinning....

 

[Lightfoot]

I see what you're saying about the reed valves, but the pressure only comes out of that hose when it's running. There would be no difference in operation or the leak whether the reed switches were allowing bleedback or not as the path is the same.

Nothing leaks "out" of the switch when it's running. The full pressure is coming from the line running to the unloader valve. I guess the unloader valve is supposed to accept that pressure but it doesn't.

My head is spinning....

I would suggest call Master tool tomorrow and explaining your symptoms. They obviously know more than me (wouldn't take much).

I had one of those plastic lines on a compressor years ago. I ended up taking it off (after replacing it twice). If the compressor was used a lot, the line would actually get hot enough to melt pinholes in it. I had to change a few things around, but i ended up replacing it with a small copper line using compression fittings, and never had any more problems.
But i still believe from re-reading all your post, that you need to check the reed valves, it sure sounds like that is the prob. At least you wouldn't spend any money on it till you have eliminated that possibility.
Just trying to help

 

[jduncan459]

I 100% appreciate all help! After reading the comments on the Master tool website, they described my problem almost exactly as a check valve and unloader valve issue. So I ordered both parts.

Hopefully I can get busy in the shop soon!

 

[Lightfoot]

Let us know if that cures it
Good luck, John!

 

[Jbullfrog]

My guess is it has a little piece of debris in a seat. and they got you to bite on parts you don't need. instead of just cleaning it.

 

[jduncan459]

My guess is it has a little piece of debris in a seat. and they got you to bite on parts you don't need. instead of just cleaning it.

I tried cleaning both valves and it didn't help. Believe me, I would rather do that than buy parts if I don't have to.