Backhoe MF 185 Backhoe Hydraulics

[Altenbrauch]

I have an MF 185 backhoe and can't get the boom to lift. The front loader works fine, aside from needing to work some air out of the lines. When I bought it, one of the hydraulic lines on the boom was busted and it had been setting for awhile. The line has since been replaced, but the boom still doesn't move. The front loader works fine. None of the levers work for the rear boom or the stabilizers. You can feel pressure on the hoses going to the manifold. It looks like there's pressure getting to the bottom cylinder, but not through the lines. My uncle took it apart and put it all back together. I found a heavy duty spring about one inch long on the ground afterwards that looks like it's for hydraulics, and I think perhaps he removed it and didn't put it back, but he doesn't remember anything about it. I've checked the hydraulic valves under the controls but they all have springs. I'm not very experienced with hydraulics, and am looking for advice on whatever might be the problem and where that spring is from.

I've attached some photos of the spring and the backhoe. My uncle replaced just the one line (fifth photo), but also took off the metal line on the bottom hydraulic cylinder (sixth photo) because it was bent and not getting a good seal at the base (fourth photo--hydraulic fluid does reach there). I tried taking off the hydraulic line that was replaced to see if any fluid was reaching it, but nothing came out.

The spring is about an inch long and maybe 3/4" wide, so it's fairly large compared to the smaller pressure springs in the valves. Could it have come from the metal line (sixth photo)?

Any help would be very greatly appreciated.

 

[Altenbrauch]

Okay, I figured out where the spring came from. It goes just under the bolt on the metal line of the cylinder (photo six); I checked the other line and it had a spring in the same place just like it.

The boom still doesn't move, however. Nothing happens when the levers are used.

 

[PatrickS2222]

Maybe an idea to loosen each hose out of the hydraulic valves half a turn or so, one at a time, and see if pressure is reaching that point. Then do the same at the cylinders. The hoses may have also been mixed up - even by the previous owner or someone helping him.
Consider it from a viewpoint of the logic involved in which lever should control which action in which direction, then trace the hoses involved and where they should connect.
Keep us updated on your progress.