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Quincy 308 rebuild
- Thread starter Line crew
- Start date
No it does not have high pressure intake loader. The pressure release is just piped into the head. This is only the second time in my 59 years I have tried to fix one of my compressors. So any help would be greatly appreciated.
American Locomotive
Well-known member
Is it possible to assemble pump backwards? I thought I remember reading once that it was possible to somehow put the pump in backwards on these compressors.
MacMcMacmac
Well-known member
Did you replace the o ring on the oil pump input shaft where it's driven by the crank? If that is missing you won't get any oil pressure? If you disassembled the oil pump and it is a vane type, the sliding collar that the vanes run inside may not be in the correct position. This type of pump is supposed to self adjust for either direction. The vanes pull the ring collar they ride inside to expose the proper oil ports. The travel of this ring is limited by a small pin in the crankcase. It rotates to position and stays there. It theory it's all automatic. In practice, the vanes rarely have enough drag to pull the ring to the proper position and you need to lightly tap it into place with a sharp center punch. Some Quincy's have an oil pressure relief valve built into one of the crank counterweights. This valve closes when the pump is spinning to keep oil pressure up in the crankshaft, then it opens up and dumps oil pressure when the pump stops. This allows the unloaders to work almost instantaneously instead of having to wait for the oil pressure to drop by natural leakage. That valve may be malfunctioning. Some have an Allen screw plug in the front crank throw that could be leaking. The oil pressure regulator may have failed or be leaking internally.
The pump can be installed incorrectly if it is the gerotor style. You have to orient the pump based in the rotation of the flywheel.
The pump can be installed incorrectly if it is the gerotor style. You have to orient the pump based in the rotation of the flywheel.
Last edited:
arkansawer
Well-known member
- Joined
- Apr 28, 2013
- Messages
- 51
my 310 has a oil splash ring on the crank. no oil pump. the 308 is the same, i think
arkansawer
Well-known member
- Joined
- Apr 28, 2013
- Messages
- 51
I replaced rings, rod bearings, crank bearings & race, shim, seals, gaskets, and o-rings. Cleaned old values. Took oil pump apart cleaned it. Do I need to prim the oil pump to make it start pumping?
where is the oil pump located on your pump?
MacMcMacmac
Well-known member
Some of the smaller ones can come with splash lube. The only 308 I've seen was pressure lubed.
I replaced all o-rings. The pump has 1 spring that pushes 2 metal (pump paddles ? ) 4 of them two springs, rotate to pump oil. I do not see how they could draw oil up to the pump without oil in the pump. In the bigger pumps like 325 will it draw oil when it is dry?
Post a pic.This has a oil pump.Hear it unload at the end.
With Quincy having over 100 roc’s on some pumps some do and don’t have bells and whistles.
The youtuber that rebuilds a 325 outside on a table also mentions other pumps.
He’s saved me a few times.
With Quincy having over 100 roc’s on some pumps some do and don’t have bells and whistles.
The youtuber that rebuilds a 325 outside on a table also mentions other pumps.
He’s saved me a few times.
MacMcMacmac
Well-known member
I replaced all o-rings. The pump has 1 spring that pushes 2 metal (pump paddles ? ) 4 of them two springs, rotate to pump oil. I do not see how they could draw oil up to the pump without oil in the pump. In the bigger pumps like 325 will it draw oil when it is dry?
You could always put something like a bit of Vaseline in there to help seal things up. Brother in law used to do that with Detroit gear pumps
Did you rotate the collar in the pump?