Quincy 325 Pump Question/Issue

[roblouvasz]

Hi Y'all. The unloader on the top of the 325 pump leaks air out of the blow off hole after the tank is up to pressure (see arrow in second photo). I know when the compressor turns on there's a burst of air when it starts and stops, but there's a tiny bit of air leaking out afterwards. Other than that, it runs fine. The unloader closes the valve after the oil pressure builds to 15 psi (which I think is a bit low) and it builds air pressure just fine. BTW, it's actually not a Quincy air compressor. The tank is another manufacturer and the motor is a Marathon 6hp. In my neck of the woods CH Reed is the parts supplier, but their shipping is ridiculous. Does anyone know of another supplier with reasonable shipping? Any input would be great.

 

[roblouvasz]

Anyone?

 

[WhoWhatNow]

Exactly were is the leak? Have you sprayed soapy water on the unloader valve and checked for bubbles? Mine leaded from the unloader diaphragm. Quick and easy fix:

http://www.ebay.com/itm/QUINCY-1565...148470&hash=item41be07959f:g:AtgAAOxyldpR9rn-

 

[bsaint]

It's an unloaded starting system not a fail safe for low oil pressure. 15 psi is all it needs. Most compressors only get a half a rotation before they are loaded up.

 

[roblouvasz]

I've already replaced the diaphragm in the unloader tower and the leak is still there. I've checked a couple of other sites and found out that the issue may be rust/corrosion on the valve assemblies. I'm going to give Quincy a call and talk to their techs today.

 

[roblouvasz]

Exactly were is the leak? Have you sprayed soapy water on the unloader valve and checked for bubbles? Mine leaded from the unloader diaphragm. Quick and easy fix:

http://www.ebay.com/itm/QUINCY-1565...148470&hash=item41be07959f:g:AtgAAOxyldpR9rn-

It's right from that hole.

 

[American Locomotive]

I don't see how its possible for air to leak past the diagram if it's in good shape. Are you sure the leak is actually from the unloader, and not air back flowing through the tank into the compressor?

 

[MacMcMacmac]

If there is a constant blast of air coming from the hole in the unloader tower, then there is a path to the tank that is not sealed. The first thing you should check is the HP exhaust valve. Quincy usually used the HP exhaust valve as the check valve, instead of using one in the tank.

 

[redmondjp]

If there is a constant blast of air coming from the hole in the unloader tower, then there is a path to the tank that is not sealed. The first thing you should check is the HP exhaust valve. Quincy usually used the HP exhaust valve as the check valve, instead of using one in the tank.

That's my guess as well. One downside of the steel valves on this compressor pump is that they can rust if not used regularly. There are plenty of repair videos on youtube that show how to take Quincy valves apart.

 

[rompn63]

I had that same problem and it was the check valve on the line to the tank.

 

[bsaint]

I had that same problem and it was the check valve on the line to the tank.

If that's the case it's a leaking discharge valve. You shouldn't need an in tank check valve for this unit.