Relatively new to Telehandlers but some experience working on other heavy equipment. Recently bought a used VR90B that only steers in 2-wheel mode. This VR90B has the electric switch and solenoid cross-over valve instead of the manual valve found on earlier VR90Bs and VR90s. When the solenoid valve is energized either way (for crab or 4-way steering), the back wheels turn only a small amount before the steering wheel locks up and the hydraulic load jumps up, loading the engine. As soon as the valve is de-energized, engine / hydraulic load disappears and steering wheel goes back to normal. I've never worked on 4-way steering before but it seems relatively simple as far as the hydraulics are concerned. Before I do something stupid though, I thought I'd ask the folks here for advice. Any suggestions on what I should try first before I waste a bunch of time and hydraulic fluid? The full story: The switch was not factory original and only had two positions (ON-ON) instead of three positions (ON-OFF-ON). One of the connectors going to the solenoid valve was pulled off and broken (probably because they didn't have 2-wheel steering with the ON-ON switch and just decided to yank the connector). When the switch was in the other position, the back wheels would move just a tiny bit and very sluggishly. I check the voltage on the solenoid and found only ~3V. I pulled the connector and checked again and found the same thing - I had 12V to ground on one wire and 9V to ground on the other wire. I decided to deal with the electrical issue when it's warmer (I'm working outside). My understanding of the steering valve is that it has three positions so the you either (a) energize coil 1 and leave coil 2 off, (b) energize coil 2 and leave coil 1 off, or (c) leave both off. I brought out a 12V power supply and connected to one of the coils. Current draw through the coil was as expected (~3.5A) and the wheels moved appropriately for about an 1/4 of a turn on the steering wheel. Then the steering wheel locks up and the engine picks up a load. This happens turning the steering wheel either direction. The behavior is the same when the other solenoid is energized. Thoughts?
No replies yet.