Thread: Log Splitter Repair

I nearly built the same flange mount system for my log splitter. I always wondered how they managed to weld the flange plate at bang on 90 degrees to the beam so that the ram would not bind when fully extended..... OK so they cheat and use shims. Ahhh shims, is there anything they can't fix?!

Simon

Originally Posted by simonl

OK so they cheat and use shims. Ahhh shims, is there anything they can't fix?!
Simon

I reckon that if someone showed them how to make and use a jig to position that plate then the shims would be obsolete....

I bolted the ram onto the splitter today. The fully extended ram needs to move about 8mm sideways and 5mm up to align the holes in the clevis and the blade. Based on the ratio of the length of the extended ram and the mounting bolt centres I need a couple of 1mm shims and a couple of 0.5mm shims. It's not critical because there's a fair bit of slop in the clevis/blade joint.

I started the motor and ran the ram back and forth a few times, but each time I got a loud hiss of air from the tank vent hole. Eventually I noticed the fluid in the supply hose was sitting about 100m below the pump. Obviously it isn't priming. I hope I haven't stuffed the pump by running it dry.

Anyone know how to prime these pumps?

These pumps should be self priming as they are whats is called a positive displacement pump and can pump fluids and gases. The only reason it would not self prime is if there was not enough fluid in the resevoir. If the damaged ram still has fluid in it and the new ram is empty then the new ram would have had to be filled from the existing fluid in the resevoir and if the resevoir does not hold enough then the fluid level may run below the pump pickup point and not prime.

The hissing air noise maybe the air entering the resevoir to replace the fluid that has left to fill your new ram.

Check the levels and top it up. You should be fine.

Simon



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Shouldn't be a shortage of fluid. We forced all of the fluid out of the original ram back into the tank.

There was definitely air coming OUT of the bleed hole. I could feel it blowing against my leg each time I extended the ram. I did it about 6 times. Air came out the hole every time.

Is that a tandem gear pump? If so why is one pump plugged off?

Originally Posted by jack620

Shouldn't be a shortage of fluid. We forced all of the fluid out of the original ram back into the tank.

There was definitely air coming OUT of the bleed hole. I could feel it blowing against my leg each time I extended the ram. I did it about 6 times. Air came out the hole every time.

I think simon is spot on and you need to check your oil level.

Originally Posted by .RC.

Is that a tandem gear pump? If so why is one pump plugged off?

It is a 2 stage pump and the plug that l think you are looking at is the plug that holds the spring for the valve that redirects the flow from low to high pressure.

It would be a good idea to make sure that the suction hose is tight, if you are getting air in that pipe while the engine is not running it is an indication that it is loose at the pump.

Originally Posted by jack620

Shouldn't be a shortage of fluid. We forced all of the fluid out of the original ram back into the tank.
.

How did you do that? Simply retracting the ram while still connected to the hydraulic system will not empty the ram. In a double acting system the ram is always full of fluid no matter what position the ram is in.

Simon


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Originally Posted by shedhappens

I think simon is spot on and you need to check your oil level.

OK, I'll get some more oil and top up the tank.

Originally Posted by simonl

How did you do that? Simply retracting the ram while still connected to the hydraulic system will not empty the ram. In a double acting system the ram is always full of fluid no matter what position the ram is in.

We used blocks of wood and a pinch bar to force the ram into the cylinder with the control valve open and the engine off. It wasn't easy. In hindsight it may have been drawing oil back into the other side of the piston by suction. Although it would have to pull the oil through the stationary pump. Since John now has that ram he holds the answer to the mystery. If you are right the retract side of the cylinder will be full of oil and my oil tank will be about 5L low.

I topped the tank up with 5L of hyd oil and the pump primed straight away. Gold star for Simon.

The oil in the tank was above the pickup point before topping up, but obviously not enough to allow the pump to self-prime. Looks like we didn't get the oil out of the ram. Be careful John!

Now I just need to make/buy some shims.

Shucks. Thanks Jack. Glad to have been able to help.

Simon

Here is some pic's of the repair, the rod had 2 bends in it, with the v blocks at each end its now .001" runout in the middle, it has .004" runout from the main bend and halfway between that bend and the end at 180 deg it now has .002".
It took about 15 ton of squishing to bend it and more than double that for the short bend.

I wore a groove in the concrete between the press and the plate so that is as good as it gets, good enough for a log splitter and likely better then a new chinese one

It got a new rod seal and clevice.

cheers, shed


ps. if you look at the rod when it is in the chuck you can see an outer ring on the face, that is the hard bit

Nice job John. Two questions:

1. What thread did you end up cutting on the end?
2. Was it full of hydraulic oil?

Cheers,
Chris

Originally Posted by jack620

Nice job John. Two questions:

1. What thread did you end up cutting on the end?
2. Was it full of hydraulic oil?

Cheers,
Chris

G/day Jack the thread for the clevis was 33 x 2, it screwed on nicely at 1.22 DOC

It had about 4 ltrs in it, half a plastic bucket.