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Discussion Starter #1
I have an MF 185 backhoe and can't get the rear arm 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 to the rear bucket was busted and it had been setting for awhile. The line has since been replaced, but the arm still doesn't move. 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. Any help would be very greatly appreciated.
 

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pressure check the pump first.
then pressure check at the manifold.
then at each cylinder (they should all have the same reading)

After all that works. Try to see what happens if you try to move the suspect cylinder manually with no hoses. Pay attention the the shaft. If it doesnt move at all by hand, look to see if there was recent welding done in the area. I have seen numerous welders that will attach the ground to that nice shiny rod and as soon as they start the arc where ever. Zot! No more cylinder.
 

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Did he just replace the hose? Hard to tell size of spring, it does look like a spring that could have come out of a valve but wouldn't just fall off tractor. Do any of the other functions work at the rear? Does the backhoe have a separate pump from the loader, PTO pump maybe?

Oops missed the picture, I see it is plumbed into the loader valve. If nothing else works on the backhoe, wonder if something is stuck in that valve, all though I would think it is just plumbed into a port, no valving involved.....James
 

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James has the pertinent question. "Do any of the other functions work at the rear?" If so, your problem lies within that valve and cylinder, concentrate on them. If not then it's quite possible that you have an fluid supply problem to the control valve for the hoe attachment. Air lock, trash blockage, etc...
 

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Discussion Starter #5 (Edited)
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.

My uncle replaced just the one line (first photo, only new one), but also took off the metal line on the bottom hydraulic cylinder (second photo) because it was bent and not getting a good seal at the base (last photo--hydraulic fluid is reaching 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 (second photo)?
 

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Discussion Starter #6
Okay, I figured out where the spring came from. It goes just under the bolt on the metal line of the cylinder (second photo); 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.
 

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Does your MF have a diverter valve up by the Front End Loader controls? Push in one end of the machine has hydraulics, and pull it out and the other end gets the oil. My Case works like that.
 
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