hydraulics question??

[glmf]

guys, I posted this in the Kioti section as well, but thought this area my appropriate also. 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,,,,,

 

[SPYDERLK]

Are you running it from the quick connects. They are restrictive at high flow. Are you using the male ends with the hi flow poppets or the ones with the ball?
larry

 

[glmf]

yes, I am using the quick connects, and they are the type with the ball. The backhoe works fine with these connections but I guess doesn't require the same flow due to the much smaller cylinders. My splitter cylinder is a 4" cylinder. Thanks for that info and do you know where I can get the high flow type???

 

[RonMar]

Sounds like flow restriction. Do you have any real tight bends in the lines? It might also be possible that the QCs for the splitter are not fully opening, or opening the same way they do when the hoe is connected.

 

[glmf]

the supply and return lines to the splitter valve are sch 80 1/2" lines with socket weld fittings and two forged unions right before the valve. An 18" 1/2" hose at the end of the hard pipes connects to the tractor QD's. Out of my splitter valve to each end of the cylinder is two more 18" 1/2" hoses. There are no sharp bends in the hoses.
I will remove the return QD today somehow and run and see how much my supply pressure drops. Thanks for the help

 

[kennyd]

I think your fine, just seeing normal restriction caused by the fluid flowing faster at the higher RPM, kind of a parasitic loss per say...

Have you checked the pressure when the backhoe is? I'll bet it's the same.

 

[glmf]

thats a good point kennyd, I haven't checked the pressures with the hoe on. I will have to come up with a way to do that,,,,thanks

 

[SPYDERLK]

I have bought the higher flow male QC tips at Tractor Supply. I think theyre good for about 2GPM more than the ball tips. Probably knock down backpressure 50psi or so. It would be nice to run straight thru coupling connections - but so inconvenient and messy.

I outfitted my Mahindra with a pressure gauge ported directly from the output line of the pump. Imagine my concern when I saw 700PSI with all valves in neutral at 2500RPM. Delivery at that speed is 17gpm. That pressure @ flow says 7HP is being used to do it. Just pumping fluid thru the system at that rate. What a waste! No wonder the hydraulics get hot when youre just mowing using the mechanical PTO drive.
larry

 

[glmf]

well, thanks guys for all your help, as the problem is solved. As per somones 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.

 

[MJPetersen]

Glad it was simple when it came down to it. Bet you do not forget about that screen again. And just think now you are the expert in this and when somebody has a similar problem, you will have the answer.

Mike