JD 6920 hard /stiff steering / tls fault

[Cotfarm]

Hi any body had problems with hard/ stuff steering on a 20 series John deere I have one all the pressures are ok until u use the steering then the pressure is low making the steering hard work sometimes there's no steering at all until u pull a spool to boost the pump I think it's the orbital unit but there £ so I am go to check the o rings in the spool today
Any body that this before
Thanks

 

[NZ Tech]

This can be the bottom pump bearing and pump shells failing.

What is the steering pressure taken at the steering dr in the priority valve?. Pressure with no valves in use and pressure turning the wheel?.

 

[Cotfarm]

About 500 psi normally but after calibration of the front sup got it to 1500 psi also cleaned check valves on Ls block under the trailer brake and cleaned priority valve
Then steering is light not right
Also had a new pump about 16 months ago ( still doesn't mean it hasn't failed again )
Thanks for the reply

 

[NZ Tech]

Ok and what pressure if you dead head the scv?. So itll be max pump pressure and thats 2950psi correct?.

Steering pressure should be 200psi or so at the steering dr and at max steering lock should be 2700psi, thats the top rh dr in the group of 3 the top lh is the ls dr and bottom dr is system pressure and standby will be 460psi and max pressure is 2950psi. Ls will depend on if the tractor has 3 scvs and 300series scvs.

So check the pressures and list then down for me please.

 

[Cotfarm]

Max pressure is correct
It's 3 300 spools and tls and trailer brake
I will check the others and come. Back to you in half a hour

 

[Cotfarm]

Right standby is 450psi
And steering loaded is 1500psi max
And If i dead end a spool as well it's 2700psi

 

[NZ Tech]

Ok.. So more a load sense issue from the priority valve I'd say. When did the tractor start doing this- just randomly?.

 

[Hummin-Cummins]

Do the hydraulics pump randomly on it's own??
Had similar problem before was a valve in load sensing broken in 2, was easy fix once we found out which valve had broken!!

H-C

 

[Cotfarm]

It's been doing this for 2 years
Any sorted it today found a blown seal replaced and al working great
Thanks for the helps and replys

 

[NZ Tech]

Where was the seal?.

 

[Cotfarm]

Nz tech
It's was on the end slice/cap on the third slice
For ls
Also think we had some dirt in the tls valve ls system which was loss giving problems

You any good with 6430 std transmissions
Got one that losses drive after 1 hour /hot and losses pressure In the forward pack until the pressure switch turns off the drive
But still drives fine in revs

 

[NZ Tech]

Cracked forward clutch basket.