John Deere 4100 3 point not working

[Jdeere4210]

I am trying to fix my neighbors John Deere 4100. It sat for a couple months this summer and when he went to use it in the fall the three point hitch wouldn't raise or lower. When you move the lever nothing happens. The front loader and power steering work fine. I played with the rate of drop knob and still nothing. I changed hydraulic fluid and cleaned the screen. The linkage is in tact and the shaft going into the case turns when I move the lever but it doesn't seem to have much resistance to it. I took the link arms off to make sure that nothing is binding up. The arms are currently in the raised position. I feel that since there is not much resistance on the raise/lower lever that probably something inside the case must be the problem. I don't know what to try next. Any help would be greatly appreciated. Thanks.

 

[beenthere]

Is it outside or in a cold shed, or where it is warm temp?

:welcome: to TBN

 

[Egon]

Have all the controls been checked.

 

[Jdeere4210]

I have the tractor inside my garage, 55 degrees.

 

[Jdeere4210]

Egon, what do you mean have the controls been checked? The lever moves up and down freely.

 

[Bigfoot62]

Can't speak for Egon, but if the auxiliary hyd. valve is open, the lift won't operate.

 

[Jdeere4210]

What is the aux hydraulics valve?

 

[DFB]

Well the system relief valve is located underneath the rockshaft housing. There my be an odd chance that some foreign debris or a bad spring cause it to remain open and dump to sump. Fairly easy to remove clean and inspect.

Since you say have neither up or down control.

Then there is also the rockshaft control valve itself located under the seat at the front of housing that also has internal directional relief valves. They also dump to sump. This is what directs flow to raise lower and lock in position the lift arms by movement of the rockshaft cylinder.

Along with correct system pressure their also has to be proper pump flow
System pressure tests are normally run to isolate problems,

And are you saying it was known to be working ok when first parked?

Here's a diagram from JD parts online on the main relief valve

 

[Jdeere4210]

Yes worked perfect when parked and then didn't work when it was used next. Loader and power steering hydraulics work great. This is a gear model.

 

[Jdeere4210]

He has a 60" mowing deck on it. Pretty much just uses the tractor to cut grass.