John Deere 855 Loader problem

[BobLong855]

Greetings, I have an older 855 JD with a 410 loader on it, has worked fine for a good spell. Was curling the bucker to roll an small old stump out, blew a connector apart in steel tube on the loader. Cut the line, put a new compression ferrel, worked for a while alright but started locking up. It was on the lift operation of the bucket. It would lock up, sometimes could lower bucket, shove control into float and free it, or sometimes restart the tractor. Most of the time would have to bleed the hose at the check valve quick coupler. Rotated hoses in function, lift and lower ok, but transferred the problem to curling the bucket in. I got on it 3 or 4 days ago and worked it for a while, cylinder would travel some and stop, kept working it and it started working, worked it for a good while, but came back out to use it and as soon as I pressured it up, it locked again. Any suggestions? Thank you.

 

[Rock knocker]

I bet it's in the valve, for some reason it is not allowing the return circuit to open. Such a problem would be weird on a valve as simple as a tractor FEL valve, but that's my guess.

 

[Rock knocker]

Crossed hose circuits would do that too. Look at your valve and mike sure both hoses on a single spool go to the same function on the impliment (boom vs curl) as opposed to one side of the spool going to boom and the other side going to curl.

 

[BobLong855]

Crossed hose circuits would do that too. Look at your valve and mike sure both hoses on a single spool go to the same function on the impliment (boom vs curl) as opposed to one side of the spool going to boom and the other side going to curl.

That's possible, I've had the hoses off several times and they are not marked or identified. Thanks for your suggestion, I'll trace them out.

 

[BobLong855]

That's possible, I've had the hoses off several times and they are not marked or identified. Thanks for your suggestion, I'll trace them out.

Traced hoses to Quick couplers and configured correctly. Bled them all, removed check valves and cleaned for any blocking debris. Played with it for a pretty good while, functions would work properly with an occasional lock on lifting the boom. Thought it was fixed. Every time I drop the bucket flat and pressure it down it locks up. Have to bleed the pressure off the check valve to uncouple. Rotated check valves same thing. Rotated hoses and with 150 lb of weight in the bucked it locked and wouldn't lower until the pressure was bled off it.

 

[Rock knocker]

What check valves?

 

[BobLong855]

I guess I am mistakenly calling the fittings on the ends of the implement hoses that depresses when quick-coupled check valves. When it {#3 quick coupler] locks up with pressure, you cannot uncouple the hose or relieve the pressure by pushing it against something until you bleed it off. After you bleed it some the valve will release.

 

[Rock knocker]

Those are Quick Connects (AKA QD's {Quick Disconnects}) it is common for pressure or remnant pressure to hinder their operation

 

[beenthere]

The fittings (QD's) once connected should not be causing any "lock up" or full flow of hyd. fluid, as you describe in the OP.

That "check valve" in the male tip will sometimes get enough pressure build-up depending on the temperature or movement of an attachment that makes it difficult to re-connect the couplers and require pressure relief.. but that just restricts connecting. As Rock knocker says.

Something else going on here.. hope with your help and more description we find the answer. I wonder if the QD's are not fully connected?

 

[Rock knocker]

Now if the QD's aren't compatible with each other male to female, but appear so.....