Progress! Manual Hydraulic splitter won't work

[Black Jaque Janaviac]

OK. I picked up one of those Harbor Freight manually operated hydraulic splitters almost a year ago. It worked excellent for quite a while although I can't say I split a lot of wood with it. It's too slow for volume splitting. I got it to use as a back up for the stubborn logs and making kindling. For that, this thing is excellent.

But the "low gear" pump will not move the ram. I can't figure out what's wrong. I remove the piston and the cylinder on the pump and could find nothing wrong. It doesn't leak fluid when I pump it. It behaves like there's a valve stuck open. But I can't figure out how to get at the valves.

Does anyone know hydraulic mechanics? I tried emptying the hydraulic oil and replacing it but that did not help.

Unfortunately it really needs the low gear pump. Since the reason I use it is for the stubborn logs, I need that power.

 

[Backwoods Savage]

Good luck.

 

[JustWood]

Blown seal.

 

[Black Jaque Janaviac]

Blown seal, I'll trust you on this.

But if it was the seal on the pump's piston wouldn't the fluid lead out every time I pumped it? I.e. the fluid getting past the seal. Instead, it just seems to be pulling fluid from the reservoir, then pushing it right back into the reservoir. In fact I can see this happening when I open the plug on the reservoir. I compared the "low gear" pump to the "high gear" pump and I can see the reservoir level go down as I pump the high gear and the ram goes forward. When I pump the low gear the fluid just rises and falls in the reservoir.

 

[MasterMech]

I haven't played around with any of these but is there a check valve on the low pump somewhere? Pump piston seal? Maybe it's like a hyd jack and there is a release/retract screw open?

 

[kevin j]

There is a check valve on the inlet, and another on the outlet. Push piston in = pushes fluid out the outlet check. Pull piston back out, the outlet check closes from pressure from the log, and the inlet opens and draws in fluid.

If you see tank motion the fluid is going back and forth in and out of the inlet check.

I have no idea how to find the checks on your machine, but they are usually a simple ball and light spring, hiding behind a plug of some sort (for machining reasons so they can make the seats)

You might be able to remove the pumping piston and blow air or cleaner back through the seats and checks to clean out.
My bet is either dirt in the check, or broken spring, or broken ball on the inlet side.

 

[Black Jaque Janaviac]

Hmm.

I've done pretty much nothing with the jack since I first posted this. Now the low-gear pump works . . . sort of.

If I remove the reservoir plug and pump the pump it moved the ram. If I put the plug in, it will move the ram only so far.

It's like the reservoir is sealed tight so that when the oil is pumped out of it, the vacuum works against the pumps. Is this the way it should work? Or is there supposed to be some way for air to replace the fluid in the reservoir?

When I plug the reservoir and operate the pump I can feel the suction in the pump. If I jack the pump back and forth real quick I can feel the pump piston get pulled back down and the ram barely moves. But if I jack the pump 1/2 way and pause to let the pump's cylinder fill it works.

 

[Dune]

The vent may be blocked.

Seperately, pumps don't nesasarily leak if an internal seal blows.

 

[Black Jaque Janaviac]

Vent?????

Now where would that be located?

 

[Dune]

Vent?????

Now where would that be located?

Usualy it is just a small hole in a plug.

 

[Black Jaque Janaviac]

OK, So that little rubber plug in the reservoir isn't really supposed to be air-tight?

If I can't find a hole I can certainly make one. But if the manufacturer didn't make one???

 

[Black Jaque Janaviac]

I started taking things apart on my hydraulic splitter and found a ball check that was not moving. I jimmied it around with a toothpick and pulled out this metal shaving!

Now at least the slow-speed pump works. However, the reservoir still builds up a vacuum and the ram slows down a bit. Could this be because I monkeyed with the "adjustment" screw? I checked out a "hyjacks" website which had some helpful drawings - although I found it quite obnoxious. Evidently I am an idiot for messing with the adjustment screw. Although there was nothing in the owners manual that suggested that the screw should not be messed with. . .

 

[MrWhoopee]

"They said I'd blown a seal
I said, "Fix the damn thing
And leave my private life out of it
Okay pal?"

"Wet Dream" by Kip Addotta

Sorry, I just couldn't resist.

Craig

 

[onetracker]

"They said I'd blown a seal
I said, "Fix the damn thing
And leave my private life out of it
Okay pal?"

"Wet Dream" by Kip Addotta

Sorry, I just couldn't resist.

Craig

thanks for taking that one craig. i was trying to figure out how to tell the old joke while keeping us PG rated.

welcome to the forum.

OT