It's a 1998 massey 860 backhoe. The tilt and crowd on the back arm sticks on. When you let go of the level if won't return to neutral. It wants to stick on and you would have to pull it back. Also if you had a bucket on it the ram is loosing pressure immediately and the bucket falls from either full crowd or tilt. Is it seals gone in the ram Or A problem.with the valve chest ?
Bad seals in the ram are the most common reason the bucket or what ever function will creep down but it could be a valve problem as well. If the valves are sticking, first make sure the linkage isn't binding or full of dirt. If that's all good the return to neutral springs on the valve spool could have broken or are weak from fatigue. You could disconnect the linkage and see if the valves stick on their own. The backhoe valve may need new O-rings/seals or possibly need to be rebuilt. It's possible O-rings/seals have failed and there are little pieces in the valve causing problems. Might not be a bad idea to inspect the hyd. filter if nothing else is obvious. Make sure a new filter is available first. Hopefully it's not a big problem. I don't know what type of valve or if parts are easy to find for it. Some other parts for ** hoes are hard or impossible to find.
It just came on all of a sudden. It wouldn't be too bad If it was a ram seal but I'm not liking the sound of ripping the valve block
Hopefully it's not too difficult to fix.
To get at the o rings in a valve block does the block need to be split? What would you see if you opened the 4 Allen screws for that section in trouble in the picture below?
Most of time no. You can take the end caps on the spools off with the valve in place. First thing you need to do is clean everything really good and then see how much access you have