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[hondaracer2oo4]

I know a lot of you guys are farmers and do a lot of mechanical repair on farm equipment. I have a 1967 case 430 backhoe. The front bucket  tilt cylinder is a double acting cylinder. It will drift prettyquickly when even no load is on it. Dips down from horizontal to vertical with only about 250 pounds within a minute or two. The other day I blew the ollld hydro line to the raise bucket side of the cylinder. I pulled off the bad hose and raised the bucket arms up in the air. The bucket dropped right away and hydro fluid came quickly out of the open port. This suggested to me the oil is leaking around the piston??? I also thought though that the oil would have to bypass the actuator lever seals though???

[mlappin]

Not sure how tough a Case cylinder is, I’ve attempted to rebuilt the cylinders on our JD loader and backhoe, they use packings instead of o-rings/backer rings, I just run em to our local hydraulic shop and let them mess with those blasted packings, it’s their bread and butter after all.

One thing you can try, reverse the hoses going to that cylinder, if it still does it most likely leaky seals in the cylinder.

Another way to tell, take the pin out of the rod end, take the hoses off, if you can shove the cylinder in and pull it back out easily then the packings are shot on the piston. Good seals/packings/o-rings should have a considerable amount of resistance on the rod, bad ones will have nil to none.

Far as the valve, plumb a 3000PSI gauge into each hose one at a time, activate the valve for that hose, if the pressure drops back off immediately you either have a bad load check or a scratched spool, if it’s anything like our Oliver and Whites with the variable displacement Vickers pumps the load checks can be replaced quite easily, I can do it in less than five minutes, if its a scratched spool your SOL. A new valve will be required, don’t goto Case unless you’ve recently hit the lottery, our JD loader has a standard 2 spool Prince valve on it that most likely came from Burdens Surplus Center. If you can’t lower the loader or dump the bucket with the engine off, then you have load checks, if the bucket dumps or the boom lowers with the engine off, you don’t have load checks.

Clear as mud?

[slimjim]

Coming straight from a man who has gotten his hands ( and coveralls dirty ), great explanation Marty!

[hondaracer2oo4]

Thanks guys. Everything is clear. I have rebuilt other cylinders on the tractor and they used o rings and backers. I'll have to try flipping the hoses but I think they might not be long enough to reverse. I wish I could reverse cylinder direction. They mounted the cylinder so the bucket has more down force power than curl power. That was dumb.

[mlappin]

Thanks guys. Everything is clear. I have rebuilt other cylinders on the tractor and they used o rings and backers. I'll have to try flipping the hoses but I think they might not be long enough to reverse. I wish I could reverse cylinder direction. They mounted the cylinder so the bucket has more down force power than curl power. That was dumb.

You’ve described both our JD loader and the JD backhoe, the old Kelly loader and our skid steer. You have to get into the newer heavy duty stuff before they used the full power of the cylinder and extend to retract the bucket.

[hondaracer2oo4]

Apparently they are packings. That's what it says when I looked it up. Why are packings a pain?

[mlappin]

You need a special tapered tool to get the packings to start into the bore, think like a tapered ring compressor for piston rings in an engine. I tried a regular ring compressor once, it can be done, not sure its worth the hassle compared to how fast a hydraulic shop can do em, this was my experience with JD cylinders and packings, maybe Case will be different.

[hondaracer2oo4]

Well I had done the backhoe stabilizers before. I also found it to be impossible to get the gland nut back over the piston rod. I called the local hole in the wall hydraulic guy. I told him my issue and asked if I could bring them in for him to do. He was awesome and said that what he does is just take a bench grinder to the end of the piston rod where it slides over the gland nut and round it off to s taper. He said that there is no harm in rounding this area of the piston. Low and behold the gland nut slid right over after that. I did find it very difficult to get the new gland nut seal into the gland nut. Basically had to twist the seal into a figure 8 and get one side into the groove and then untwist it. Very difficult in only a 1.25 inch piston rod gland nut. No room to move the seal around.