Hello, I recently bought an L225 and realized the lift would not stay up when I attached a mower to it. I pulled the lift cylinder and pistion out and did notice that the Oring between the cylinder and cylinder head had a worn area, so I figured, simple fix! Well I replaced all the orings including the pistion, and it still won't stay up. It falls about an inch per minute or so. I tightened the knob on the cylinder head to the lock position, and it still falls at the same rate. I did notice some scratches on the cylinder wall and was wondering if it could be leaking past the oring there. Can you hone out the cylinder to make it smooth again, or will this cause more leakage? I can't figure out where else it would be.
L225 Hydraulic Lift
- Thread starter tjhopkins
- Start date
I'm really perplexed now. I went ahead and honed out the cylinder till it was nice and smooth. I put the piston back in it and filled it with oil and put the cylinder head on and turned the flow control to lock. I then put it on the shop press and pressed down on the piston. I couldn't get one drop of oil to leak out of the cylinder or around the piston, and I was putting some serious pressure on it. Put it all back in the tractor, hooked up the brush hog, and it leaks down, even with the flow control knob in the locked position. There was no difference from the day before. This is one of those times I just need to walk away from it for a while and let the frustration wear off.
See Vic's counsel --- probably time to look at the control valve. Sounds like there isn't any leak at the piston so the only other logical choice is the control valve.
Question -- as the TPH leaks down does the control lever move down also??
Question -- as the TPH leaks down does the control lever move down also??
Maybe I need some help understanding this. I guess I don't see what the spool valve has to do with this. Please correct me if I'm wrong, but if the flow control valve(under the seat) is in the lock position, and the cylinder is full of fluid, there should be no way for the fluid to exit back out of the cylinder, and make it back to the spool valve your refering to. The fluid should be "locked" in the cylinder. This proved to be correct on the shop press test that I did, and should work the same when put back in the tractor. If the lift stayed up in the locked postion, but bleed down in the unlocked positon, I'd suspect the spool valve or something else. But, it bleeds down at the same rate either way. I'm beginning to wonder if the cylinder has some play in it at the when installed in the tractor and is slightly separating from the head, allowing fluid to leak past the oring between the cylinder and head. This couldn't have happened on the shop press. After all, this was the oring that looked bad when I first started looking at this. I'm going to do some more checking/testing in this area before I move on.
I'll give you my "Reader's Digest" version while openly admitting that I don't know which control valve you have or how it's constructed. I'll reference my control valve and then someone else who knows yours will need to provide more help if you need it.
My control valve is a "position control" valve. It has a couple of check valves inside that could allow hydraulic fluid to bleed off to the transmission case if they were malfunctioning. So, even though no fluid was returning to tank or transmission from the "rate control" valve that you're focusing on, the TPH may lower on its own if fluid was bleeding by the check valves inside the control valve and returning to the transmission case.
Do you have the manual for your control valve??
My control valve is a "position control" valve. It has a couple of check valves inside that could allow hydraulic fluid to bleed off to the transmission case if they were malfunctioning. So, even though no fluid was returning to tank or transmission from the "rate control" valve that you're focusing on, the TPH may lower on its own if fluid was bleeding by the check valves inside the control valve and returning to the transmission case.
Do you have the manual for your control valve??
I've got an I&T manual, but it doesn't have a lot to say about the operation of the spool valve other than how to remove and reinstall it. There is a diagram of it, and there's not much too it. I think yours is a bit more complicated than mine. This just has three positions, up-neutral-and down. No position control. I did do some more playing with it today and discovered that if I relieve the pressure from the spool valve to the cylinder while the flow control valve is in locked position, the lift will stay up. So, that eliminates the o-rings on the piston, and at the cylinder head. I also discovered that the lock mechanisim is simply a cone shaped plunger. When the fluid from the cylinder pushes against this plunger, it seats and prevents the fluid from escaping from the cylinder. The only way I figure what's keeping the plunger from seating is some back pressure between the spool valve and cylinder. Since I was able to prove that there is no leakage at the piston, cylinder head o-ring, and locking plunger, the only other variable left is the spool valve. I pulled the spool valve today, and didn't notice anything obviously wrong with it. No scratches, looseness, gunk or anything else. I replaced the o-rings on it while I had it open, but it still leaks down. The only thing I know left to do is spend the 300+ dollars on a new spool valve assembly and see how that goes. If that's it, kudos to Vic for pointing that out in the first place! I'm still having trouble wrapping my mind around what's actually happening in there.
I'm in a pickle now. I went through two dealers trying to get a new control valve. They were both told by Kubota the the spool valve has been discontinued and no replacement is available. Not sure where to go from here!!
It doesn't appear that there is any seals in the body of this valve and the spool actually looks good, so, I'm drawing at straws here, is it possible that the spool is not centering correctly in the neutral position, causing some leakage? Is that adjustable? I'm bout out of ideas.
It doesn't appear that there is any seals in the body of this valve and the spool actually looks good, so, I'm drawing at straws here, is it possible that the spool is not centering correctly in the neutral position, causing some leakage? Is that adjustable? I'm bout out of ideas.
did you happen to find out if there are cross parts that can be used? perhaps they used that same spool on other models?
there is a L-200 in our local salvage yard, not that it would be any better then the one you have now,
there is a L-200 in our local salvage yard, not that it would be any better then the one you have now,
Nothing that doesn't have the same discontinued part number. There is not a parts list for the individual parts, it came as an assembly only. I've searched all over the internet and found nothing so far.