Joystick

[dieselscout80]

Only thing semi-rebuildable on the valve would be the centering spring and detent assembly. Not really anything else to rebuild in the valve since the spool is a metal to metal fit in the bore.

That’s the thing the valve’s movement and detents feel just like they always have felt.

I am leaning toward just replacing it with a new one.

 

[oldnslo]

Certainly not a normal run of the mill failure that you are experiencing. If I remember correctly you swapped the lines from raise / lower to the curl / dump spool and then the loader raised and lowered but now curl / dump didn’t work so it certainly points to the lift / lower spool being the problem.

Not sure what else to try at this point.

 

[dieselscout80]

My service manual has the loader valve in the hydraulic section.

The attached pictures show the relevant flow diagrams for the positions not working and the parts breakdown.

It looks like in the first two flow diagrams the oil flow is not flowing properly as it is only lowering in the float position.

Also in the last flow picture (bucket control) oil in going to lift cylinders rather than stopping B on the lift spool (top one listed as #1).

I wonder if the load check valve listed in bucket control could be messed up (lower right of diagram). But it looks it’s part of the spool #1.

 

[oldnslo]

Load checks are typically separate from the spool and usually just prevent oil flowing from the load back into the pressure port. Normally if one fails it will allow the load to drop when trying to raise vs preventing it from lowering.

Also looks like your valve is a series parallel design where return flow from raise lower is directed back into the curl - dump circuit so you can lift and dump or lower and curl simultaneously. Did your loader do that before it quit working?

 

[dieselscout80]

Load checks are typically separate from the spool and usually just prevent oil flowing from the load back into the pressure port. Normally if one fails it will allow the load to drop when trying to raise vs preventing it from lowering.

Also looks like your valve is a series parallel design where return flow from raise lower is directed back into the curl - dump circuit so you can lift and dump or lower and curl simultaneously. Did your loader do that before it quit working?

Yes it would lift and curl before this happened.

I forgot a detail that happened a year or two ago. I was lifting a load and it would drop slightly before lifting.

 

[oldnslo]

Yes it would lift and curl before this happened.

I forgot a detail that happened a year or two ago. I was lifting a load and it would drop slightly before lifting.

That might indicate a load check had a piece of crap in it or was not seated correctly. Did this correct itself or was it still dropping some before lifting a load?

Note: I edited my prior post possibly while you were replying so may be double check.

 

[dieselscout80]

That might indicate a load check had a piece of crap in it or was not seated correctly. Did this correct itself or was it still dropping some before lifting a load?

Note: I edited my prior post possibly while you were replying so may be double check.

It kinda kept doing on that day (more than a year ago), but it didn’t keep doing it.

 

[oldnslo]

Diesel
In studying the valve Assembly on img 1158 you posted the centering mechanism item 9 screws into the end of the spool. If this has worked loose and backed out a turn or two it could potentially allow lift to drift up vs being centered and prevent lowering since spool would no longer be traveling to correct distance.

If you decide to take this apart removing cover item 2 may or most likely will allow item 6 & 8 to fall out.

 

[dieselscout80]

Diesel
In studying the valve Assembly on img 1158 you posted the centering mechanism item 9 screws into the end of the spool. If this has worked loose and backed out a turn or two it could potentially allow lift to drift up vs being centered and prevent lowering since spool would no longer be traveling to correct distance.

If you decide to take this apart removing cover item 2 may or most likely will allow item 6 & 8 to fall out.

I like your suggestion.

Background my joystick was working loose when I first got the tractor. I finally got it stopped by adding a locknut to the bottom of the shaft.

So it may have vibrated #9 loose and be worth checking.

It will probably require removing the whole valve to get to #2 due to the hard lines.

 

[oldnslo]

If you can access the end of the valve the joystick connects to you could possibly measure the spool travel from spring position to fully pulled in that direction for both the lift and curl functions. You would need to measure accurately since may only be looking at 0.03 to 0.05 inches difference (possibly more) in start position or movement amount.

If this thought of #9 working loose is correct there still should be a position on lower that works but it might be when you are pushing into detent so kind of jumps past that spot. I could also be wrong on that thought.