Okay, so I realize it's not a car or truck, but it has an engine, transmission, differential and 4 wheels, so it's close, right?

Anyhoo, I was wondering if we have anybody onboard who's familiar with these things. It's a Case 580B, and my boss bought it about a month and a half ago. I've been working on the beast, and run into a snag or two. Here's the biggest problem I'm having:

I rebuilt the boom cylinders, in fact one of them was the first cylinder I had to rebuild. When I first put pressure to it, the seal blew and shot out a stream of hydraulic fliuid. Now, the hydraulics on this thing are supposed to be self-bleeding, but it seems there is air trapped in the system somewhere. When using the hoe, it will bounce violently at times and also will not pull up into the locked position. I have to back it up against a tree or push it into place with the forklift to lock it. When it's locked, it unlocks just fine but will not come all the way back up again.

I have subsequently rebuilt the other boom cylinder since it began to leak soon after, and repalced one of the cross-over hoses. At that time I tried to bleed any air out, but there seems to be no improvement.

A tractor repair guy I know was driving past the other day and I flagged him down and asked him about it, he was stumped, never seen the like. The service manual says nothing about it, it agrees that the system is self-bleeding.

Has anyone experienced this problem and have any suggestions? It's very hard to operate the thing when it begins to bounce like that, and as sloppy as it is, I'm sure it's not doing all the bushings any good.

Thanks, -TD

 

I used to operate my neighbor's Case in the summer digging fill lines. Last summer was my last year doing that. I'm a HS senior as of 8/9/05

Anyway's It sounds like it has an air lock. I know it's self bleeding but that doesn't mean crap. Sometimes it will get an air lock it won't bleed off. Extend it all the way. Crack the line at the ram. slowly push the ram in until fluid squirts out. make sure the ram is full of fluid. tighten it down and then so it do the other line on the ram while some one does the controls. With the engine off. Then both sides of the ram must be full of fluid

Take the lines and run them into a bucket of hyd fluid and run that circuit for a couple of minutes to see if any air locks come out.

That's what i would try. and do it to all the rams on the hoe end.

Also makesure the cap to the resivor is off while you run the circuit. A good 5 gal bucket should work. just run both lines into it and run it in both directions.
Keep the resivor levels up too.

How sloppy are the controls?
I'm not an expert but it's worth a try
DT

 

I know this is not much help now, but for some reason I am thinking it might be in the control valves(either leaking by or air in them), I have a buddy that is real good with tractor hydrualics. I'll ask what could be up.

 

That's what my second guess is.

DT

 

I have never worked on a case. But I have resealed many JD cylinders. Sounds like the oil has nowere to return. Are you sure that the cylinder head is all the way out against the stop or in the correct spot. If that is in just a little it will block the flow.

 

I'm pretty sure the problem is air trapped in the cylinders, you should see how the sucker gets to bouncing as the air is compressed, it's like there's a spring in there. Except for not being able to pull it all the way up to lock, it has its full range of motion, and I've used it for many hours digging up tree stumps and other things, it's just getting annoying.
As for slop, almost everything is sloppy but the controls themselves feel pretty tight.
I'm going to work on it this morning, the guy who stopped by the other day made almost the same suggestion as DT466, he just didn't go into as much detail. I'll let y'all know how it goes. Thanks for the suggestions thus far, keep 'em coming! -TD

 

You may already know this but I thought I'd mention that the lock on these machines is an overcenter position, therefore to get it to lock you must bring it up as fast as possible and when you see it hesitate, move the lever to the down position quickly.
As far as the bounce, I have no idea.

 

Well, bled it out some and got rid of most of the bounce, and I can get it to lock now if I extend the boom all the way and, like dwightir said, bring it up fast. The lock is spring loaded so it clicks in and locks automatically, it's just a matter of being able to bring it up enough to latch. It wouldn't do it before, but it does now. Thanks for the help guys!
and dwightir, welcome to FTE! -TD