Hello all, I'm new to form and apologize if this has been covered in past. I did a search and did not see anyone with the same issue so figured I'd make a post. I have a Case 40Xt that the Lift arms drift down & bucket tips forward with out moving controls, it does this on its own. When operating machine, I constantly have to move the controls to pick up the loader arms, and also constantly be tipping the bucket back. It's basically falling due to gravity. If it was just one or the other, I would think there would possibly be a bad o-ring on a spool valve, but since both functions are doing the same thing, it make me wonder if there is a common relief valve for both circuits? Or am I over thinking this, and is this something stupid like a switch not turned on? I don't have a operator manual for the machine, and just bought it. If there is a common relief valve or both circuits can someone point me in the direction to where its located. Any input or advice will be greatly appreciated, Thanks in advance.........
Welcome to HEF Bird4ss! There is not a valve common to both circuits. Did this problem start at the same time? Did you buy the machine with the problems already existing? Likely, you have the same problem in both circuits - I would check cylinder piston packings on both lift & tilt cyls before anything else. :drinkup
I bought machine this way. I did some tests, and are pretty sure the piston seals are bad in both tilt cylinders. I raised loader arms, and rolled bucket all the way forward (the direction it wanted to leak off to). When I did, the loader arms stopped drifting down, this told me the piston seals were probably shot? I then capped/plugged the tilt cylinders, and raised loader arms. The bucket still rolled forward, which it should not have done as the system should have been hydra-locked. What was throwing me off was that both the lift arms and tilt was being effected, that's why I thought there was possibly a common return of relief for the two functions. I'm going to pull tilt cylinders apart tomorrow an see what's going on in them. Any input is greatly appreciated............
OK, you need to mention that you bought it this way. It changes the whole story. Obviously you bought some "mechanic's" problem. First thing I would look for is making sure the spools are in the right holes. After that the spool to bore clearance. After that the valve may be cracked.
Sorry for the lack of info, I bought loader at auction. I actually am a Mechanic/machinist, and I buy/repair skid loaders as a hobby, so I'm new to on-line forms, but not to twisting wrench's. I'm just not real familiar with the 40XT's, and until I started doing a little trouble shooting, I to thought it was a problem in the valve as both the lift and the tilt were drifting off bad. But when I capped/plugged the tilt cylinders, the lift function works great. I pulled the tilt cylinders apart this evening, one is toast as the bore is gouged and piston is grooved bad. This thing is odd, the cylinders look identical from the outside, but the internals are slightly different between the two cylinders. Did case make a slight change in cylinders between model years of the 40XT, or does this thing have a cylinder off a 1840 or similar machine? The cylinder that is bad, has a 63mm (2.483") piston, 35mm shaft, and the piston is held on by a nut like a normal hydraulic cylinder. The better cylinder, that just needs seals replaced, has a 64.37mm (2.532") piston, 35mm shaft, and the piston looks to have internal threads, as the piston screws onto the shaft, and then is held from backing off by a set-screw. All in all, since the cylinder tubes both have the same outer diameter, and the threads in cylinder tube for end cap don't looked like they will interfere, if I have a long enough boring bar, I should be able to bore the grooved cylinder, and put a piston in bored cylinder with same OD as my better cylinder has. It would be great if I can find a 64.37mm (2.532") piston, but if not I will be whittling one out on the lathe. I looked on case's website parts break down, but it does not give a good picture of the cylinder internals. Once again, and input is always appreciated.....
Yes, there is a difference in cylinder configuration. The cyl without the piston retaining bolt is off a later model machine than the one with the bolt. The case parts website does show the different cylinder types - with the machine serial number breakdowns for the changes.
I see now, I was looking under the "(08-17B) - CYLINDER - TILT" on case's website, when I should have been looking at the "(08-17) - CYLINDER - LOADER BUCKET". So, I have one from before serial number JAF0374549, and one after serial number JAF0374550....... I was thinking tilt cylinder was for the bucket, but obviously I should have been looking under bucket cylinder. Thanks for your help..........