JD 4210 3 point intermittenly not working

[bulldogmack407]

Ok so we have a John Deere 4210 compact tractor in the shop and the customer states that the 3 point does not raise. My friend (the owner of the shop) said he witnessed the 3 point not raising a brush hog. He said there seemed to be a dead spot about half way up, he also said when he turned the steering wheel it then lifted the 3 point with no issue. One of the biggest problems we have now is we cannot replicate the problem. The tractor has an FEL, my friend also said when the 3 point would not lift the FEL still worked fine. All hydraulic fluids and filters have been changed, John Deere told us to take apart the valve block under the seat but i figured id throw this question out there for you guys rather than just start pulling everything apart.

 

[bulldogmack407]

Also, the rate of drop adjuster does not do anything.

 

[Tx Jim]

Also, the rate of drop adjuster does not do anything.

By R-O-D not doing anything do you mean one can't lock 3 pt in raised position by fully closing screw?

 

[J_J]

If the rate of drop doesn't keep the 3pt locked, after the 3pt is raised, then you do have problems.

With a good pump, the loader will work correctly unless the 3pt is relieving, and causing back pressure upstream.

Hydraulics:
Type: open center
Capacity: 6.3 gal [23.8 L] (gear)
6.8 gal [25.7 L] (hydro)
Pressure: 2125 psi [146.5 bar]
Valves: 5
Pump flow: 7.0 gpm [26.5 lpm]
Total flow: 12.3 gpm [46.6 lpm]
Steering flow: 5.3 gpm [20.1 lpm]

 

[bulldogmack407]

The ROD does not lock the 3 point or change the speed of the 3 point in any way. I cannot find any diagrams on this tractor at all! If i had a hydraulic system diagram it would be a HUGE help. Also where do you guys think i should start troubleshooting?

 

[J_J]

The ROD does not lock the 3 point or change the speed of the 3 point in any way. I cannot find any diagrams on this tractor at all! If i had a hydraulic system diagram it would be a HUGE help. Also where do you guys think i should start troubleshooting?

The rate of drop is jamed .

Remove and clean.

 

[Tx Jim]

J_J
Could you please explain how the R-O-D screw can keep 3 pt from raising?? I understand how a stuck R-O-D can't control lowering speed. My understanding is the 3 pt valve has a pressure(raise) & return(lower) to control 3 pt and all the R-O-D is control how fast the 3 pt lowers by control how fast oil leaves 3 pt return valve or when closed completely should 3 pt position. Thanks,Jim

 

[J_J]

I did not say anything about raising the 3pt.

The descent knob is inline with the dump circuit of the 3pt, and controls the flow out of the cyl.

 

[Tx Jim]

Forgive me for my poor reading comprehension. I thought you mean't by cleaning R-O-D the 3 pt would start operating(raising) correctly. Sorry,Jim