hyraulics question??

glmf · Jul 20, 2007

Just built a 3pt log splitter. Tractor is a CK20hst. I have the backhoe so the remotes were already there on the back of the tractor. Having some issues and would like to here comments from you guys with any insight. If my tractor is idled down under 1k, the splitter acts as I think it should, if maybe a little slow. I have a pressure gauge on the supply line and it shows very little pressure with the splitter valve in its open center position. As I increase rpm's on the tractor, the pressure on the supply line also rises until it is about 500psi just at rated pto speed. This doesn't seem right and I know all the lines are plumbed correctly. Everything works OK and in the correct direction, and splits wood fine. All my lines are 1/2 inch so I can't believe that is a restriction. Have taken everything apart and checked for restriction and nothing. Even changed the splitter valve(new one off ebay) to an old one I had laying around and no change. Why is my system pressure so high with the splitter valve in its open center position. I am used to engine powered log splitters that dumped back into a vented tank so there was no pressure on those systems with the valve in the center position. Does the Kioti system have pressure in the power beyond loop all the time? This is actually loading the tractor with the splitter valve in the open position. If I slide the lever on the tractor that controls flow to the remotes in its center(flow stopped) the tractor will unload. These problems are all agravated as you increase the rpms. Seems fine at the lower speeds but moves too slow, get over 2k on the tach and things really jump up. Can't figure it out and need help,,,,,

Trac-Tech · Jul 20, 2007

I am presuming that the gauge you mention is teed into the supply line to the splitter? If so, the pressure you are seeing is the back pressure created by the return oil and most likely the quick release coupling. No matter what you do, you will get a back pressure and it is probably as high as you want it at 500 psi. This is more so of an issue due to the fact of the size of the tractor, it is using excessive horsepower that you do not have to spare and hence the need to try to get it down to say around the 300 psi mark. To confirm this is the actual cause, remove the QRC from the return hose on the splitter and run it directly into the trans filler without the coupling. I would expect that you will see a dramtic decrease in the back pressure. Please remember, you need some back pressure to allow instant working of the splitter when you operate the control valve. Without this back pressure (residual line pressure) you would have to wait for the pressure to build up before anything would happen. If I am correct, the only way around it will be to make free return back to the trans. You can also experiment with different couplings as these can have a dramatic effect on the pressure and sometimes cause more problems than they are worth. It can also be that the female coupling is not compatible with the male and they will not push one anothers pintal off their respective seats which then causes a restriction. I hope this helps, if you have any more questions, please ask and if I can I will help.

glmf · Jul 21, 2007

thanks for that info, I am going to try and plumb it without the QRC today and see how much the pressure drops. Thanks for that info

kennyd · Jul 21, 2007

I posted reply in the hydraulics forum...

Please don't double post, it make it a lot harder to help you when answers are in two different forums.

And, I agree with Trac-Tech...

glmf · Jul 21, 2007

Sorry for the double post, as yes, I see your point about not all the answers being in one forum. But for now,,,well, thanks guys for all your help, as the problem is solved. As per someones suggestion, I used a longer hydraulic hose I had and went all the way from the end of my return hard pipe to the fill spout on tractor. Just stuck the end of the hose in the fill spout and duct taped it. Fired it up and no problems. No pressure at all with the splitter valve in its open center position, didn't matter what the rpm's of the tractor were. So this told me that the restriction was in the QD. Just so happen to have the next size up Parker/Aeroquip quick disconnect laying around so start to pull it apart and guess what. On the Kioti remotes there is a screen behind the QD fitting and this screen was clogged solid. There is my problem, cleaned the screen and put everything back together and works great, again, regardless of RPM(flow rate).
Now, I was super careful about cleanliness when I put this splitter together, and when I first ran it, I put the return hose in a bucket until I got a few gallons of oil out, then hooked up the hose to the QD. The oil in the bucket was nice and clean with no debris. The gunk that was in there was really hard packed and seemed to have been there awhile and didn't look like anything familiar. Guess it could be from the building of the tractor, not sure and the tractor only has 30 hrs and the splitter is the only other implement other than the factory installed backhoe(probably dealer installed I guess). But anyway, things are working fine now, and thanks again for all the help.

Trac-Tech · Jul 22, 2007

Glad to hear all is well now, is the gauze you found actually part of the Quick release coupling or is it in the fitting that the couplig screws onto?

glmf · Jul 22, 2007

the screen is part of the bulkhead fitting that the QD screws onto. The bulkhead fitting is 1/2" compression on one end for the steel tubing that comes from the loader valve and back to the sump. The other end of the bulkhead fitting is threaded for the QD fitting and in the middle of it is two nuts that capture the mounting bracket, thanks again for your help