Case backhoe controls acting weird

[jshwhite]

This is on a 1979 Case 580c, but probably applies to about any backhoe. I recently got the machine and have been getting it fixed up (actually more like fix, break and repeat!). Today it finally worked long enough to dig with it for a while, and I'm not sure if there's an issue in the spool valve or what.

First of all the controls don't "double" very much. I'm an experienced operator on wobble stick controls and I'm still trying to get used to this 3-stick + foot swing, but regardless, it will not double-function very well. If I'm lifting the boom and I try pulling the dipper in the boom will almost stop. Curl/dipper is better but still not great. A normal/smooth scoop with the bucket would entail curl+dipper+boom all at the same time, and I find myself having to feather the controls alternating between functions a lot more than I feel like I should. Is this normal for this type of 3-stick control, or is something wrong in the valve?

Another thing is that there seems to be some bleed over. Moving the boom would also cause a bit of swing. And then today I blew a swing cylinder seal and the fluid would spray out the heaviest when I lifted the boom ...that doesn't seem right to me.

And to top it off, none of this is very consistant. Might do it sometimes, and might not. What's going on? I don't know much about the valves, but is it possible there are seals or o-rings leaking, or things getting stuck? This machine did sit outside for a couple years before I bought it. Is this something I can DIY, or should I take it to a hydraulic shop?

Thanks! I always appreciate the great help and community we have here on TBN.

 

[jshwhite]

Thought I'd post an update on this in case anyone was wondering. I took the whole valve body into the hydraulic shop and he went through it all. Said there were over 100 o-rings in it and the majority of them were bad, broken, or missing. That explains the bleed over. The double functioning seems better too. I haven't had a chance to run it much because I have another leak, but from the few minutes I did run it it seemed a lot better.

 

[etpm]

I have a 1970 something 580CK. It is the only backhoe I have ever used. Mine also doesn't do doubling very well. I just thought that's the way it was supposed to work. I watched backhoe operators on other machines and tried to emulate them but my machine is pretty worn and I learned on it so I figured the problems I had with doubling was mostly me. BTW, I didn't even know the term "Doubling" until I read your post.
Thanks,
Eric

 

[ddbackhoe]

Thought I'd post an update on this in case anyone was wondering. I took the whole valve body into the hydraulic shop and he went through it all. Said there were over 100 o-rings in it and the majority of them were bad, broken, or missing. That explains the bleed over. The double functioning seems better too. I haven't had a chance to run it much because I have another leak, but from the few minutes I did run it it seemed a lot better.

If Im remembering correctly, the hoe runs off the loader valve pb. Have you checked the relief valve setting? have you checked pressure and flow from the pump (about 2200 psi and 25 gpm)?

 

[jshwhite]

I have a 1970 something 580CK. It is the only backhoe I have ever used. Mine also doesn't do doubling very well. I just thought that's the way it was supposed to work. I watched backhoe operators on other machines and tried to emulate them but my machine is pretty worn and I learned on it so I figured the problems I had with doubling was mostly me. BTW, I didn't even know the term "Doubling" until I read your post.
Thanks,
Eric

This is the first 3-stick I've run, so I was thinking maybe it's just the way they are. I'd like to hear from others who have run these.
I did feather the sticks and get it to double boom/dipper, but I had to be careful not to pull too much on one stick. Maybe I just need some hours running it to get used to it, or maybe there's something wrong with it.

 

[jshwhite]

If Im remembering correctly, the hoe runs off the loader valve pb. Have you checked the relief valve setting? have you checked pressure and flow from the pump (about 2200 psi and 25 gpm)?

I haven't checked that but that's a good idea. I need to get a gauge. Recommend any in particular?

 

[etpm]

This is the first 3-stick I've run, so I was thinking maybe it's just the way they are. I'd like to hear from others who have run these.
I did feather the sticks and get it to double boom/dipper, but I had to be careful not to pull too much on one stick. Maybe I just need some hours running it to get used to it, or maybe there's something wrong with it.

Well, on my 580, the sticks need to be barely pulled. This was kinda hard for me to learn. At first I would pull one stick or the other but could never get both to work at the same time. Then, after thinking about what I had seen professional operators do, and knowing I should be able to get two sticks to work at the same time I just started being more delicate with my motions. And that's when I learned how to move the hoe back and up at the same time so that the bottom of the ditch ended up level.
I asked a really good backhoe operator how to get this motion perfected and he told me to start with level ground and practice keeping the teeth just an inch from the ground as I moved the hoe closer to the machine. He also told me that I needed to fabricate a blade 40 inches wide that attached to the hoe so that I could dig a flat bottomed ditch 40 inches wide for my infiltrator septic system. I still have that blade. It just bolts to the hoe, fits over and covers the teeth on the bucket. It worked very well.
Eric

 

[DJ54]

I had the same problem first with my old Case 310B, and then my 480C both 3 stick/foot swing. I cut my eye teeth on a '74 Ford 550 4 stick and loved that old hoe. Multiple functions could easily be done fairly quick, yet smooth. From that to multiple hydraulic excavators from Gradall's with direct connect levers to hydraulic spools, and newer various model track excavators with electric over hydraulic wobble sticks.

Getting the hang of the Case hoes was a whole new ball game. I had the same problem with seemingly double function/bleed over and seemed the function with the least resistance would be the one to move when doing a double function. I too just figured the o-rings were worn allowing this to happen. This was 10 years ago but thank goodness for the internet and what few heavy equipment forums were around at the time. Come to find out it wasn't all me, just different type of hydraulic systems. What I was used to was equipment with closed center systems, but the Case uses an open center type. The paragraph below describes both systems, and why seemingly why when doing a double/triple/quadruple function, the function with the least resistance would function faster. Like when digging a trench, then lifting the boom, extending, swinging, then dumping the bucket, the swing/dump function would speed up as they had the least pressure resistance. So when picking up/extending/swinging, pressure was passed on to the swing (with less resistance, or pressure needed to perform the function) speeded up along with dumping the bucket. Once I figured out what was going on it just took some extra feathering of the controls to smooth things out. Hope this helps...


The difference between these is the construction of the directional control valve as well as the type of hydraulic circuit being used within the system. In an open center system, the flow is continuous and pressure is intermittent, whereas in a closed center system the flow is intermittent and the pressure continuous.

 

[ddbackhoe]

I haven't checked that but that's a good idea. I need to get a gauge. Recommend any in particular?

not really, the cheapest you can get because it doesnt have to be super accurate. Northern tool has some reasonably priced. Fittings, hose and adapters ring up quick too. Since the 580 is kinda big to haul around easily, maybe your local hydraulic guy will let you “rent” one.
Some of my adapters are in the bowl, like the 12 jic x 8 jic hose because I couldnt get a straight fitting.

guages

 

[jshwhite]

I had the same problem first with my old Case 310B, and then my 480C both 3 stick/foot swing. I cut my eye teeth on a '74 Ford 550 4 stick and loved that old hoe. Multiple functions could easily be done fairly quick, yet smooth. From that to multiple hydraulic excavators from Gradall's with direct connect levers to hydraulic spools, and newer various model track excavators with electric over hydraulic wobble sticks.

Getting the hang of the Case hoes was a whole new ball game. I had the same problem with seemingly double function/bleed over and seemed the function with the least resistance would be the one to move when doing a double function. I too just figured the o-rings were worn allowing this to happen. This was 10 years ago but thank goodness for the internet and what few heavy equipment forums were around at the time. Come to find out it wasn't all me, just different type of hydraulic systems. What I was used to was equipment with closed center systems, but the Case uses an open center type. The paragraph below describes both systems, and why seemingly why when doing a double/triple/quadruple function, the function with the least resistance would function faster. Like when digging a trench, then lifting the boom, extending, swinging, then dumping the bucket, the swing/dump function would speed up as they had the least pressure resistance. So when picking up/extending/swinging, pressure was passed on to the swing (with less resistance, or pressure needed to perform the function) speeded up along with dumping the bucket. Once I figured out what was going on it just took some extra feathering of the controls to smooth things out. Hope this helps...


The difference between these is the construction of the directional control valve as well as the type of hydraulic circuit being used within the system. In an open center system, the flow is continuous and pressure is intermittent, whereas in a closed center system the flow is intermittent and the pressure continuous.

Now this is some helpful info! That explains it. So it's not just me, or my old cranky machine. Thank you!
Now my question is, why? Is there some advantage of the open center system? Compared to the closed system where you can run one function full-open and feather in a little of the other, I'm not sure I like this one.