Hello everyone. Having trouble with a Case 580K boom swing cylinders drifting/leaking both direction. It’s slowly drifting downhill depending on slope I am on. The more incline, the faster it seems to move. Recently, both swing cylinders were leaking at the wiper seals and were rebuilt at the same time. I also had issues with several wipers leaking around the backhoe spools. Ended up pulling each spool and replacing the o-ring on top and bottom of spool along with wiper seal for valve body. Since this, the drifting problems have started and not sure which repair may have caused it. No signs of external leaks on cylinders or spools/valve body. I did have the issue of not being able to swing fully to the right but a new cam follower on the swing sequence valve fixed this issue. Has anyone ever experienced these issues before? Appreciate any advice.
Not familiar with your unit, but sounds like the rebuilder may have cut or nicked a seal during insertion. Or course this is assuming the cylinder walls and piston had no damage before starting. It only takes one nick to make it drift either right or left on an incline.
That's what I was going to say.
Cap the swing cylinders off then push one outrigger down and see if it still drifts, if it does it the cylinder, if not then it's in the valve.
If you don't have these already, get some from Amazon. They're less than 50 bucks and will pay for themselves in THF as well as keep trash out of your hydraulic system. I have two sets.
Got a set on the way. Appreciate the advice. Thanks. Once the caps get here I will try this and report back.
Hi, just the thread I was looking for, I have an Case ‘85 780B. My boor drifts to the right.. even up hill. Is it safe to assume it’s on the valve body? Bad spool or bad spring?
Finally was able to cap off the swing cylinder hydraulics and the boom does not drift either direction. Safe to say it’s valve related.
I’m confused, you would think it, the other way around?
HH, he took the valve out of the equation and no more drift. So valve the problem.
Yeah but he capped the swing cylinders off and trapped the oil which also would prevent any drift.
Whenever a spool is removed, the quad rings should be replaced. I see in your drawing they are labeled "O" rings. Quad rings have a square profile. Very different from an o-ring which has a round profile. It is very easy to damage them when they are inserted in the valve bore. There should be details in the service manual about installing the spools in the bore.