View Full Version : Into virgin territory with hydraulics

Tony Zona
08-12-2016, 6:42 PM
The other day the two-stage hydraulic pump lost the low range in my 22-ton log splitter. Oddly it kept splitting good mostly O.K. with only the high stage, but very slowly.

The new pump arrived this afternoon, and tomorrow will the the big day for me: My first venture into hydraulics repair or replacement. I bought the pump, the spider and the Lovejoy fitting that connects the pump shaft to the engine shaft.

I'm a little concerned about air in the hydraulic line after I am done. Does anybody have any pointers for me? Or should I not worry a lot about that?

The wood splitter factory guy said it is not a difficult weekend warrior job, but I know when a hose was replace in my front end loader, it took some time for air to work its way out. It wasn't a big deal, just a little disconcerting for a while.

What should I watch out for in replacement?

I have never done this before.

John Ziebron
08-12-2016, 10:49 PM
Tony, the air will purge itself out simply by exercising the cylinder. You may have to do this many times but you'll know that the air is gone once the cylinder starts working at normal speed with no jerking. Just make sure all your connections are sealed and please wear safety glasses or better yet goggles if you have them when you fire it back up. High pressure hydraulic fluid leaks can be very dangerous. Good luck.

Jerry Bruette
08-13-2016, 1:04 AM

I'd pour some oil in the pump after you hook up the suction line. You can pour it in through the discharge line, I'd make sure the cylinder is full of oil too.

Tony Zona
08-13-2016, 6:00 AM
Thank you. Safety glasses are a must.

Bruce Wrenn
08-14-2016, 9:34 PM
Check in local phone directory and most likely you can find a place that can rebuild your old pump. Last year I had to rebuild cylinder on my log splitter, which I built in 1986. Local hydraulic repair place had all the seals and "O" rings in stock.

Tony Zona
08-21-2016, 4:44 PM
It all worked out O.K. I got the wrong pump set-up from the vendor, and had to raise the engine a couple inches to make room for the return elbow. I didn't know that until I was about to connect the pump, after installing the Lovejoy adapter.

I could not transfer my old elbow, which is shallower than the new one, because the pump return line opening is about an eighth-inch bigger than my current bad pump. And there is some kind of nut opposite the unloader valve on the pump, I think, that I don't know what happens when you loosen it. My fear was that loosening it on the new pump would ruin or otherwise hurt the pump. (I still wonder what the nut does.)

It turns out that I could not get the return hose onto the new pump elbow, and could not find an easy way to adapt that one-inch pump elbow to a 3/4-inch return barb. Desperation is a funning thing. I got a hefty one-inch hose and managed to get two inches of a good section of the old hose into the new return hose. It serves as a bushing, if you will.

Of course I spilled a lot of hydraulic fluid when my drain cans overflowed while I was working on the return hose connection. I should have drained the reservoir to start with but thought I could work quick enough to keep from spilling more than a small canful. Wrong.

I connected up the hoses, filled the fluid reservoir and put on a face mask, not just safety glasses, as wisely instructed. The machine fired and the cylinder worked beautifully on the first pull. Later in the day I was splitting 3-foot diameter logs and the machine was going through them easily.

It is nice to see how well it performs when it is working with a functional two-stage pump.

Thanks again, folks, for your pointers.

(I will be keeping an eye on that jiggered-up return hose connection, but it ran for three or four hours just fine. I will still be suspicious of it until I can find a way to made a better "bushing."

Simple Green cleaned up the spilled hydraulic fluid after I i wiped most of it up.