Another loader problem

[moosehunter]

I have a 1994 NH 655. The loader will dump but won't curl back up. This problem was intermittent for the last six months or so but is not intermittent anymore. The tractor has mechanical level control but the problem does not seem to be in the linkage. I'm pretty sure it is in the loader hydraulic block. The linkage all moves but when I try to curl the valve acts like it has a lock on it. I have tried pushing the valve directly but it is hitting something solid. Before I could wiggle the handle and get it to work. I'm thinking I'll need to disassemble the block to see what is keeping the valve from moving.
Any thoughts before I start tearing it apart?
mh

[mike_belben]

Lets start with the basics. 

At the control valve, youve got the handle end of the spool with whatever type of link moves the spool fore and aft in the spool block bore.  On the opposite end you should have a back cap that houses the centering spring.  

Lets first pull that cap and see that the spring hasnt snapped or bungled in there.  While this is apart and tractor off, verify that the spool is making a full stroke both ways.  

After that get a clean bucket and pull the curl hoses from the tee couplers.   At idle, with glasses on, stroke the valve briefly each way to see that we are getting the expected shot of oil out each hose when called for.  



A green light through all these will resolve most suspicions of the valve itself and we can move on to see if you have any load checks or cylinder problems.  

[moosehunter]

Thank you Mike, I'll try to make time in the next few evenings and go through your suggested checks.
mh

[Hilltop366]

Had a similar problem with a Case 580, We disconnected the bucket level control linkage at the valve and it the valve worked feely so started to try to find the problem, it turned out to be a metal tube and rod in the linkage would make contact (the rod would bottom out in the tube) too soon and it would act like the bucket was all the way back when it wasn't. the cure was to remove the tube and clean it out with a drill. Worked like new after repaired.

[snowstorm]

Had a similar problem with a Case 580, We disconnected the bucket level control linkage at the valve and it the valve worked feely so started to try to find the problem, it turned out to be a metal tube and rod in the linkage would make contact (the rod would bottom out in the tube) too soon and it would act like the bucket was all the way back when it wasn't. the cure was to remove the tube and clean it out with a drill. Worked like new after repaired.

what he said

[moosehunter]

I have experienced what hilltop mentioned. The tub will get ice in it in the winter. I'm very sure this problem is not that.
mh

[mike_belben]

Any kind of mechanical helper that has linking to the spool for auto level or whatever feature is surely a first suspect to cross off. I hadnt even thought of those.  

[moosehunter]

Thank you Mike for leading me down the right path. I took this off the offending spool valve

 


 
The small disc above the housing was cocked sideways and blocking the travel of the spool valve. Looks like it maybe should be held in place by an E clip, I just took it out because I don't have an e clip assortment. Loader functions now, just don't have whatever safety function that solenoid offers. I'll get one soon and put it back together properly. So turned out to be a simple problem. HOWEVER, I was closing the machine up and when I shut the right side door the glass in it shattered. Doh!. Oh well, how much could that piece of glass possibly cost??!!
Thanks again for your suggestions
mh

[mike_belben]

One step forward, two steps back.  Seems i play that game every week.  

Glad you got it figured.