Hyd.Unloader problem on Quincy 325(Roger X Please)

[Anonymous-0]

Hey Roger, I"m so sorry to bother you again, but my disc on my 325 won"t load?? I took apart the valves and cleaned and resurfaced them like I did the ones on the 5120,before I did all that the hyd.unloader was leakin, so in the process of cleaning all the valves(one at a time)I took apart the hyd unloader, now it isn"t loading and unloading properly??and I have air comming out of the breather after the compressor shuts off?If I disconnect the unloader line going to the towers, it pumps up OK, but when it shuts off, the pop-off valve on the intercooler rattles a little?As soon as I connect the line back to the towers you can hear them unload,and then you can hear air comming out of the breather.I think most of my, if not all of my problems are in the hyd unloader.What do you think?Also how tight are the collar nuts supposed to be under the towers?I just tighented them down to a little more than zero clearance?All the valves were in pretty good shape, but they were real dirty.There was a little water in the high pressure valves(high pressure piston side?)I"m not sure what all this stuff is called so bear with me please.When I took apart the hyd unloader it had some dirt on top of the piston lookin thing that gets the air from the tank commin in?It"s still leaking oil pretty bad around where it goes together at the bottom where the diaphram is located.Where the air from the tank goes in to the hyd unloader there seems to be a brass screen of some sort?If I could have gotten my cd to load I might have not bothered you again, but I"m desperate, this is MY compressor, and I need it bad!!! Please help me, and GOD blesss

 

[Anonymous-0]

If this is a Quincy without a check valve in the tank, you might have air coming back in through the HP exhaust valve. You might also have a tear in the rubber diaphragm on one of your unloader towers. The HP exhaust valve might be loose in the head also. I shoot for the HP exhaust valve as the problem first, IF there is no in tank check valve.

 

[Anonymous-0]

Hey Roger, I checked the HP(I guess you"re talkin about the ones without the unloaders on them?)anyway, I checked them and they"re tight.You never did tell me how tight they"re supposed to be?anyway the unloaders have new diaphrams, I checked them anyway.No matter what I do I have oil leakin out of the unloader, so I might have a hole in the hyd.unloader diaphram.It pumps up pretty good, but when it gets close to shuttin off, it starts runnin unloaded, and WONT load back, it just continues to run??Also the tube comming out of the breather to the crank case, I assume is some sort of a PCV? on my old 310 is soldered, but my 325 it just slips in and it is NOT tight so it leaks air around that? I really think the Hyd unloader is bad?The tower on the high pressure piston side, has a line lower than the hole in the tower connected to a T going to the airfilter, and then going to this PCV thing I was talkin about not being sealed or soldered?Is this plumbed correctly?And please tell me how tight the collar nuts and HP valve nuts are supposed to be?Thanks for all your help!!!

GOD bless

 

[Anonymous-0]

Yes, oil out of the unloader = bad seals in the valve. The fact that it unloads near shutoff also indicates you have a faulty hydraulic unloader valve. The small line leading from the HP (high pressure) unloader tower sends the air that is exhausted from the pump into the cylinder head just upstream of the LP (low pressure)intake valve,inside the head just after the air filter. This is done simply to reduce noise. If you take off this small line, you should hear a brief puff of air at shutdown, then silence. If there is air coming out of this line continuously after shutdown, you have air entering the pump, either from the unloading system, via the hydraulic unloader through the signal lines, to the unloader towers (which indicates ripped diaphragm seals in the towers), or, air is coming back into the pump through the HP exhaust valve, and is being dumped out through the port on the unloader tower while the compressor is shut off. Pull that line and check for air coming out. I bet that's where it's coming from. You will need to remove your HP exhaust valve and check to see if it is sealing properly.

I don't have torque settings for the threaded collars. Just back them off before you bolt down the valve covers, then turn them on tight (by hand) with either a hook wrench, or a flat piece of steel fit into the notches, then install the tower.

The crankcase vent line just needs the O ring renewed where it slides into the crankcase. These are never very tight.

 

[Anonymous-0]

Trucks, if you are talking about the valve clamp screws, they are supposed to be torqued to 60 ft-lbs. Have to be tight enough to crush the copper gaskets under the valve, otherwise, like Roger said, you'll have air coming back from the tank into the head.