Hello. Would like to thank everyone for all of the great advice on this forum. I have a Case 580B loader backhoe. It is in fair shape, loose, lots of old hoses, rough paint, most electrics and guages gone/inop. Anyway, I was digging a stump this morning and a bucket hose blew. after getting some tools to take the busted hose off, I decided to try to raise the boom to get better access to the hose connection. As I raised the boom, and it did come up, a lot of hydraulic fluid squirted from the rupture in the bucket hose. I have a repair manual but it is hard to understand exactly what is happening inside the spool valve assembly but it seems like each of the circuits, boom, dipper, bucket, is isolated so that if the bucket spool is in neutral, there should be no flow to the bucket pressure line when I actuate other controls. Does anyone know if this is a correct assumption? I have been suspecting internal leaks inside the spool valves for a while and was thinking that the spool valves could be repaired on the machine? Also, what is a reasonable price to have a say 6 foot hose made up? Was thinking about doing three of the four of these hoses as only one is fairly new. NAPA says they do it and there is a hose shop about thirty minutes away. I still have the swivel fittings and one is leaking. I know people just eliminate them but if I could just get some new o rings it seems like an easy fix. Both swivels seem loose, can be wiggled by hand but only one is leaking. I have a lot more questions about my machine but lets just leave it at that for the moment. Archie
I am curious about this also. I have a case 480c, and I notice when I raise the boom all the way up that the boom will swing to the left if I dead head and hold the boom lever in the up position too long. It has a few other little quirks like this when I dead head some of the other functions, but can't remember them all.
Ok here's the deal there are poppet valves under each circuit relief valve top and bottom in the backhoe control valve. The O-rings become old and brittle after awhile. Remove the circuit relief valves and then look in the port and you will see what looks like a flat head screw with a wide slot, you will have to make you a tool to remove these poppets. You'll need to get the O-rings from your local Case dealer or online.
I'm not sure on that model, but in general it's common for backhoe loaders to have a self leveling bucket so you don't drop material over the back of the bucket onto your hood when it hits the top. Do you have a rod linkage from the bucket back to the control valve on the right side of the loader arm? That explains the fluid leaking from the bucket cylinder hose. I'd expect around $50 or less for the hose, depends more on the type of connector than the length of hose. A long sweep, swivel oddball thread will be much more than a straight JIC.
I had a 580 B- 30 years ago and remember some thing about taking the caps of all the valves at the bottom of the valve bank & cleaning the sludge out of them as well as pulling the top out of each spool and replacing the 0 rings. Don't remember the procedure but Coy's the man.
Thanks for that Coy. Delmer it doesn't have the self leveling. Billrog thank you also. Franklin2, I do not know what you mean by "deadhead" but quirky things were what led me to suspect the spool valves. On my backhoe, the boom swings slowly to the low side in neutral position if the tractor is not close to level. Also the swing works better to one side than the other. I do not know for sure if the cylinders are leaking internally or if it is the spool valves.
I replaced two hoses, the ones for the bucket. The hose for the dipper looked very hard to get to, looks like the cylinder needs to be disconnected and lifted. Took the leaking swivel in the boom circuit apart. It looks like it was contacting the left side boom cylinder during operation, was actually wearing a groove into the cylinder. This caused the o rings to wear on their inner sides where they are slightly shredded. Got new o rings at NAPA, we'll see tomorrow. The Parker Store charged me almost $300 for the two 6 foot long 1 inch hydraulic hoses. Will have to shop around for next time.
By "dead head" I mean pulling on the lever to make something move, and it's at the end of it's travel already. So you hear all this noise, probably the relief going off he is talking about. Unless you keep a close eye on your cylinders as you are moving things, this happens on a regular basis(at least for me anyway) and lets me know to stop pulling on the lever, that's all it's going to move. If you wanted to work on this valve bank and give it the once over, I am assuming you need to detach the whole hoe assembly from the tractor so you can get to it to work on it? I had a leak on one of my stabilizers, and it ended up being a loose hose fitting. I was able to crawl under the hoe and reach way up and got to the fitting to tighten it up. But it looks like doing anything major would be almost impossible without taking the whole thing off.
You can work on the bottom of the valve bank from the back of the machine and the top of it from inside the cab ( or threw the open window) One thing I don't advise you to do is remove or take the sections of the valve body apart.
Welcome to HEF @Archie Dunbar As you lifted the boom, gravity would want to reposition the bucket & if a hose was blown .... well, it will leak oil. However, in saying that, if the load check valves are leaking some pressure will find it's way to other circuits. With regards resealing them try reading THIS THREAD re 580E & THIS THREAD re a 580C repair - They both use same/similar valves on the backhoe as the B
Well at least I hope that your valve is the Case Valve & not the other Commercial valve......
It is the Case valve. Why is that a good thing, Case instead of commercial?
Not particularly Archie, just that all the information discussed is regarding the Case valve.
The Case valve is a lot easier to work on in my opinion is all.