JCB 2CX III steering and brake issues

[r.bishops45]

I ran into a frustrating problem with our JCB 2CX III. It's got a combined steering priority and brake charge valve, and both systems just completely quit on me!! I have no steering and no brake action at all. The weirdest part is that the steering only comes back if I activate another hydraulic function, like raising the loader or curling the bucket. It's like the system needs a kick-start from somewhere else to work.

My first thought is the priority valve, but before I tear into it, I'm just looking to see if anyone else has run into this on a 2CX III. I've been checking some specs and found the brake charge pressures are 90 BAR cut-in and 110 BAR cut-out, which seems right. But I can't find anything on the LS pressure from the steering head that's supposed to signal the priority valve.

Does anyone have a service manual or know what the spec is for that LS pressure? And any other ideas what could be causing this?? I'm trying to avoid a blind repair. Thanks!

 

[Balton52]

Had almost the same headache, it usually points to the steering charge valve sticking or not seeing the LS signal. The LS line from the orbitrol should send around 20 to 25 bar to shift the spool but if that's weak or not there, the valve never prioritizes steering. Before tearing in, I'd check for blockage or a damaged LS line, and make sure your pump is still giving full standby pressure.

 

[doobie_dub]

Your steering's acting up. It seems like the steering priority valve is stuck, so the steering and brakes only get power when something else in the system really cranks up the pressure. That gives it a jolt and gets it working, but only for a bit

 

[d0ugg.348]

I ran into a frustrating problem with our JCB 2CX III. It's got a combined steering priority and brake charge valve, and both systems just completely quit on me!! I have no steering and no brake action at all. The weirdest part is that the steering only comes back if I activate another hydraulic function, like raising the loader or curling the bucket. It's like the system needs a kick-start from somewhere else to work.

My first thought is the priority valve, but before I tear into it, I'm just looking to see if anyone else has run into this on a 2CX III. I've been checking some specs and found the brake charge pressures are 90 BAR cut-in and 110 BAR cut-out, which seems right. But I can't find anything on the LS pressure from the steering head that's supposed to signal the priority valve.

Does anyone have a service manual or know what the spec is for that LS pressure? And any other ideas what could be causing this?? I'm trying to avoid a blind repair. Thanks!

I'd put my money on the brake accumulator or the brake charging valve itself.. a faulty accumulator can dump pressure, which robs the LS line of its signal. Check if you can bleed any pressure from the brakes. If not, replacing the accumulator is a much easier and more likely fix than tearing into the priority valve, and it should get both your steering and brakes back!