Log splitter is slow aeter rebuild of control unit

[dbugman]

I have a 20 ton horizontal log splitter that was working great before I took the control valve off and had it rebuilt. I then mounted the splitter and the engine on a trailer bed. Today, I started it up for the first time and the pressure seems to be fine. It splits logs with knots with no problem but it it taking what seems like a minute to go the full length. Before, it was about 15 seconds. The cylinder is not getting very hot, even after about 10 minutes of use. It is just slow. It isn't bogging down the engine. If you reply, keep in mind I don't have a pressure gage and don't know a whole lot about hydraulics. Treat me gently.

tim

 

[J_J]

The first thing I would tell you is to put a gage on it and test the system, but you said you didn't own a gage. They may have messed with the relief. Just what did they rebuild. You can get a new valve for about $60. The valve should still pass the same amount of fluid. Perhaps the pump is running in the slow mode, if it is a two stage pump, and it will be slow.

https://www.surpluscenter.com/item.asp?item=9-7724&catname=hydraulic

 

[evan price]

Did you bleed all the air out? Air compresses, fluid doesn't.

 

[dbugman]

JJ, thanks for the quick reply.

I bought it from a high school friend about 4 or 5 years ago and it has worked well except for the hydraulic leak in the valve. It seemed to be getting worse so I wanted to fix it.

I checked all over for a new one and could not find a directional control that had the same in and out size threaded ports. So I had a local hydraulics shop rebuild it. It was leaking hydraulic fluid, especially when it hit the end of the plunge going either way. All they should have had to do was to replace the rubber O-Rings. I would have done it myself but I don't know where top buy them.

Where is the relief located, at the opposite end from the operating handle? If so, I can get in and adjust things and see what happens. I am also going to replace one of the hoses. It has a 5/8 inch heater hose on it. I never noticed it before. It is the hose from the reservoir to the pump. All the others appear to be hydraulic type hoses. I'll also replace the in line filter from the pump to the input of the valve tomorrow.

FYI, I loosened up a half turn on the high pressure connections on each end of the piston housing to see if there was any air in the system. It had a little fluid come out until it reached the ends. then quite a bit, but no air. I tightened them back up after i checked each one so it would not draw air as it travelled in the opposite direction.

I'm guessing the pressure is OK as it is splitting logs with no problem, just moving as slow as I do now. <grin>

Any suggestions will be appreciated.

Tim

 

[dbugman]

Evan, your reply came in while I was answering JJ.

I'm not sure about how to bleed out the air, other than the way I tried to by loosening up the end screws and having the piston travel in that direction and closing the connector as it reached the end stop.

Is that the way to do it?

tim

 

[dbugman]

A bit more information.

It is a Didier Splitter, I don't have the model number right now, but could get it if it is of use.

Initially, it was a complete unit with a PTO for operating from a big Toro two wheel unit.

I took the PTO off and mounted it to the engine and mounted that to the front of the splitter and had it set up so I could move it around the yard from storage to where I was splitting wood.

Recently I picked up an old trailer and mounted the splitter to the left rear (as you are standing at the hitch end) and mounted the engine and pump in about the middle of it. Today was the first time I have started it since I put it back together.

How do I tell if I have a two stage pump?

Tim

 

[J_J]

If it is a two stage. it will shift speed if the wood is hard to split. A two stage splitter will start out fast speed and low pressure, and then shift to low speed and high pressure. You should be able to set relief pressure and detent pressure.

 

[dbugman]

I have never noticed it shifting speeds. just the one constant speed, even when it is plowing through a really tough knot.

 

[J_J]

What is the HP of the motor driving the pump. This will usually determine the kind of pump, as to single or two stage. A single stage pump will take more HP to run it.

This is a typical two stage pump.

https://www.surpluscenter.com/item.asp?item=9-7503-11&catname=hydraulic

 

[dbugman]

The pump was manufactured by John S. Barnes Corp and has the following markings:
3/88 (Month/year?)
73301 (Model or Serial Number)

Motor is a B&S 8.0 HP

If I can figure out how to do it, I'll load a photo of the valve control unit and maybe you can tell me what I need to do to change the pressure relief.

As stated in previous posts, the unit has worked well since I got it until the rebuild and move to the trailer. The motor has never changed speeds, nor has the pump.

Tim