Hydraulic Issue

[quazz]

I have searched on this topic but couldn't find a solution.

Here is a summary
L3800
BH77 Backhoe
LA 524 Loader

1. I tried to take off the backhoe and moved all the levers around as I normally do to relieve pressure
2. There was pressure and couldn't uncouple the hoses
3. I started the engine and raised the loader bucket but it will only go up or curl. It does not come down unless I use the float and then it comes down normally.
4. The three point hitch is down and will not go up.
5. The backhoe or stabilizers don't move

I doubt that it is relevant but a couple weeks ago I replaced a couple of hoses on the hoe and it worked normally since then. Everything else worked normally as well.

I don't even know where to start.

Any ideas?

 

[TheOldHokie]

I have searched on this topic but couldn't find a solution.

Here is a summary
L3800
BH77 Backhoe
LA 524 Loader

1. I tried to take off the backhoe and moved all the levers around as I normally do to relieve pressure
2. There was pressure and couldn't uncouple the hoses
3. I started the engine and raised the loader bucket but it will only go up or curl. It does not come down unless I use the float and then it comes down normally.
4. The three point hitch is down and will not go up.
5. The backhoe or stabilizers don't move

I doubt that it is relevant but a couple weeks ago I replaced a couple of hoses on the hoe and it worked normally since then. Everything else worked normally as well.

I don't even know where to start.

Any ideas?

I have a pretty good idea. Your power beyond circuit is blocked - most likely at the coupler between the backhoe return coupler and tractor. Does the BH77 valve have two or three hoses going to the tractor and did you work on any of them?

Dan

 

[quazz]

Thank you so much Dan! I really don't understand this stuff at all. Yes I did replace one of those hoses. The top one in the first picture. I will take a close up and post again.
There are two hoses to/from the hoe.

Here are the pics

 

[quazz]

Here is a closer pic of that hose.

 

[TheOldHokie]

Thank you so much Dan! I really don't understand this stuff at all. Yes I did replace one of those hoses. The top one in the first picture. I will take a close up and post again.
There are two hoses to/from the hoe.

Here are the pics

Here is the short story.

Oil from the pump goes in one side of the loader valve, out the other side into the backhoe valve, out the other side of it into the 3pt valve, out the other side of it and back to the sump on the tractor. Something in that path is blocking the flow.

Start by checking the 3pt position control lever. It MUST be in the full down position.

Dan

 

[quazz]

Here is the short story.

Oil from the pump goes in one side of the loader valve, out the other side into the backhoe valve, out the other side of it into the 3pt valve, out the other side of it and back to the sump on the tractor. Something in that path is blocking the flow.

Start by checking the 3pt position control lever. It MUST be in the full down position.

Dan

Yeah I think you nailed it. The flow seems to be fine all the way to the return line and even though I disconnected the return line on both ends I can't get this line uncoupled. It is acting as if there is pressure but there isn't.

" most likely at the coupler between the backhoe return coupler " - How you knew this is beyond me. I suspect some sort of magic.

 

[TheOldHokie]

" most likely at the coupler between the backhoe return coupler " - How you knew this is beyond me. I suspect some sort of magic.

No magic. Diagnostic analysis honed by 40 years of debugging code - both mine and others. You provided the clues with a very good description of what was and was not working. Many of the very well educated professionals I helped over those years were not so well organized. Given the symptoms it was just a matter of fitting them to system operation. That said are you SURE its the coupler?

Dan

 

[quazz]

I find that with my vehicles if I can describe the symptoms accurately and precisely my mechanic is almost always right in his diagnosis. On line clarity is even more important.
Anyway I finally got the coupler apart and it looked fine and was functioning properly so I cleaned it and snapped it back together and everything is working as it should.
This one was time sensitive since I had to dig out my neighbour's water pipe so he would have water again.
You helped two people and we both appreciate it very much.