534D-6 Gradall won't steer

[lantraxco]

I don't know, but I would think the pressure required to release the parking brakes would be more than 200 psi. Anything in the manuals?

If you can tee into the sway circuit somewhere and read it with the cylinder at end of stroke, it looks like the steering priority valve has in internal relief at 2,500 psi? There's also a load sense line shown from the orbitrol to the divider, which may or may not have something to do with this problem. Been way too many years, but we'll get there.

 

[lantraxco]

I keep forgetting, you can find ANYTHING on Youtube these days, this is a great tutorial on how that whole system works:

The 200 psi you're seeing is according to this standby pressure, sounds like something internal to the priority valve is malfunctioning like the load sense relief, or possibly inside the orbitrol but you said you changed it?

 

[Bullseye Beaver F.]

Ok. I got it figured out, Finally!! It was the relief valve in the priority valve that had backed out on it's own. It takes a 7/32 allen to adjust it. It was loose, I took it out in 10 turns. It had locktite on it but it still backed out. I put it back with 11 and 3/4 turns in and that took care of the problem. Thank you for everyone's help with this and the instructional videos did teach me a few things. Glad I am a member of this group.

 

[lantraxco]

That's great! I learned something new myself, that's how it works sometimes!

 

[Lanceh21]

Hey bullseye. Where’s this valve at? I’m having the same issue. Thanks