Can you send a few pics of the valve? Sometimes it helps when we can see what your working on.
My grandfather has an old Massey Ferguson 240 with a farmhand loader on it with a weird Hydraulic problem. The loader really won't do anything and the bucket won't either (super slow) and it drifts down like crazy. I originally thought it was piston seals leaking until I operated it the other weekend. It has a simple two valve setup with a joystick, the weird thing that threw me off was that when you push the joystick all the way forward it catches like a detent and it's supposed to be in float ( I assume connecting head end to rod end) but the loader raises up. Now I think it could be in the valve, but everything's there to look at and the valve seems to be operating normally. Rear Hydraulics work just fine off the same pump, he replaced the valve a few years ago and claims it was doing similar things. I was going to put the old valve back on it and see if that changes anything. Any insight would be appreciated, also wasn't sure if I should put this in the AG section, figured a Hydraulics problem might be better suited here.
Thanks in advance,
Yea I'll have to get them scanned somewhere though. My original thoughts were that if the oil was bypassing the cylinder seals, when you lower the loader frame (put oil into the rod end), if you open the valve all the way and oil got past the piston seals into the head end then the larger area may allow it to lift instead of lower even though you are putting pump oil into the rod end initially (kind of a crazy thought). When I operated the loader I realized that (i'm pretty sure) the forward detent on the valve should be float, when I put the joystick there the loader will slowly raise up. NO OIL should be going out to the cylinder at all, so it's gotta be in the valve right? Maybe valve stuck open? Or maybe it's not float at all, but a lower detent? I was looking in the operation/parts manual and I glanced at the operation and it said that all the way forward was a float position. I feel like I'm rambling on, but I'll try to get some pictures on here, I'm not that good with computers but I'll try.
I'm almost inclined to think that maybe he's got the supply from the pump hooked into the outlet of the valve 'cause in float it should, AFAIK, just be open to the return, that might be the reason your arms come up when in float... Just my $0.02...
I've thought about lines hooked up wrong but I'm pretty sure he hasn't been into this thing in a long time and that it's worked fine after he was into it. Also I think other things might be outta wack if that was the case, seems like if he had a supply line somehow hooked to the outlet of the valve then right when you crank the key over it would put oil to a cylinder and make it raise/lower. I'll get to look at it again this weekend so keep your $0.02 coming, I need some more ideas before I go back out there. Thanks fellas.
Just some ideas. Try taking the 2 lines to the loader cylinders off and blocking the 4 ports, then see how the bucket cylinder(s) work. Then do the opposite. Check each port A & B, on the valve body with a pressure gauge while you are doing this to see if the valve is building pressure. A cylinder piston problem can cause some strange symptoms. Phil
Phil I'll definitely try capping the cylinders, and checking pressures. Sorry guys, I haven't really had a chance to do much trouble shooting, and was hoping someone had had a similar problem, maybe not with this machine but with one like it.
Hydraulics is not my strong point. I'm a trial and error type so my ideas are somewhat more primitive. Your in good hands with ATCOEQUIP. Phil
I'm in Louisville, KY, and hopefully I'll be able to find some more stuff on the tractor this weekend. The valve has two spools lift/bucket, and are connected by a linkage with one joystick which you can operate both functions at the same time. I think they are open center. Tomorrow (saturday) I should know some more, I'm at least gonna cap the cylinders and see what they're gonna do, and take apart the valve and see if anything is obvious.
Does anyone know who makes the digital pressure guage that is shaped like a regular guage, I think it might only have one transducer as well, I saw one a while back but can't remember who makes it. The set you can buy through some of the CAT dealerships is pretty darn expensive.
Louisville, cool! Been through there a couple of times. I'm curious to see how the Phil test works out. We're out here watchin' so keep us posted.