2 stage pump not pumping (wood splitter)

[adawson82]

I have a homemade wood splitter that has a Haldex Barnes pump on it. I know next to nothing about hydraulics and the splitter I inherited from my grandpa (he built before I was born). The wood splitter was functioning well, but the input shaft's seal started leaking, so I thought it would be smart to replace the seal. I tore the pump down, which was clean of any debris or metal swapped the seal out for a new one and then reassembled the pump. I reinstalled the pump onto the splitter, and now the splitter does not function at all. The hydraulic reservoir is full, and I tried priming the pump by turning the engine over with the pull string. The pump does have some fluid in it because can let the hydraulic fluid run out of the pressure line by gravity if I lower below the pump, but no fluid will pump out of the line when the engine is running. I am wondering of any troubleshooting ideas I can try.

Thanks
Andy

 

[4570Man]

I don’t think it was necessary to take it apart to change a seal. Are you certain it went back together the same way it came apart. Do you have the input and output right? Is the oil level good?

 

[adawson82]

I agree with you that it probably was not neccessary to disassemble the pump, I realized after there were set screws into the Lovejoy that secured it to the shaft.
I believe it went back together the same way as it came apart. There was a pair of large gears into the front and a pair of small gears in back of the pump. I dont know if it could go back together incorrectly?
The side that feeds the valve is a pressure line that is threaded and the other line is larger and is a barn style that utilizes a hose clamp.
The hydraulic oil is full.

 

[4570Man]

I didn’t figure it was possible to get the inlet and outlet reversed. Is the suction hose good with no obstructions?

 

[4570Man]

Did you loose the keyway shaft from the love joy allowing it to spin without turning the pump shaft?

 

[triptester]

These pumps are considered non-rebuildable. The side clearance of the gears in each section is critical, a few thousands to thin and the gears will bind, a few thousands to thick and the fluid will by-pass.

 

[nyone]

These pumps are considered non-rebuildable. The side clearance of the gears in each section is critical, a few thousands to thin and the gears will bind, a few thousands to thick and the fluid will by-pass.

Bingo! Replace the pump. They dont last for ever and are prety cheap if you consider there service life is about 30yrs.

 

[oldnslo]

I have a homemade wood splitter that has a Haldex Barnes pump on it. I know next to nothing about hydraulics and the splitter I inherited from my grandpa (he built before I was born). The wood splitter was functioning well, but the input shaft's seal started leaking, so I thought it would be smart to replace the seal. I tore the pump down, which was clean of any debris or metal swapped the seal out for a new one and then reassembled the pump. I reinstalled the pump onto the splitter, and now the splitter does not function at all. The hydraulic reservoir is full, and I tried priming the pump by turning the engine over with the pull string. The pump does have some fluid in it because can let the hydraulic fluid run out of the pressure line by gravity if I lower below the pump, but no fluid will pump out of the line when the engine is running. I am wondering of any troubleshooting ideas I can try.

Thanks
Andy

There are couple of items that could prevent this pump from working.
1) Check valve and unloading valve assembly jammed open. This would allow to circulate from outlet to inlet under low pressure.
2) Excessive clearance on the gear sets. The pump will typically still move oil even when worn just won't build pressure.
3) Missing drive shaft key like 4570 suggested.

These are a very basic and simple design so something major must be wrong to prevent any flow.