I have an 80's Clark forklift with a steering problem. It turn hard in the center and very easy near full lock in both directions. In cold weather it acts like full manual in the center 2/3s of it's travel. I cleaned out the priority valve supplying the orbitrol and it looks fine. I've bought the test fittings and tested the pressure at the priority valve, and at the pressure line to the orbitrol and at the sensor line coming back out of the orbitrol going to the priority valve. None show any pressure when the steering is hard, all 3 rise at the same rate and go to full pressure at full lock. The engine will stall at full lock, the pressure goes way past what the Clark manual calls for. The rest of the hydraulic system tests out fine. This makes me think the problem is inside the orbitrol. Dollars are scarce, and I don't want to waste them trying a rebuilt valve if that's not the problem, so I'm ready to buy a seal kit and open up the orbitrol. What are the chances that a seal kit will fix this problem? What are the chances I'll find unrepairable damage inside the orbitrol? Anyone here familiar with this problem?
Anyone? And to be clear, by pump I mean the valve/gizmo at the bottom of the steering column. I can't imagine why it works different at the ends of travel than in the center.
They all work the same way. try this link regarding a "how to" for D&A of an Orbitrol control valve (aka steering metering pump). http://tractorz.blogspot.com/2012/05/disassembling-and-assembling-orbitrol.html