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Any steering valve experts? Trimble or otherwise
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WTW
Posted 11/16/2024 18:08 (#10970094 - in reply to #10969293)
Subject: RE: Any steering valve experts? Trimble or otherwise


Winkler, Manitoba Canada
AVP_Matt - 11/15/2024 22:47

Here's where I need a hydraulic expert. I teed a pressure gauge into the pressure line at the valve and ran the gauge up to where I could watch it. Standby pressure is right about 500 and will run up between 1000 and 2000 depending how fast it steers. Steering wheel and valve make it respond nearly identical. Steering on a line it usually stays around 1000 but as soon as the valve "relaxes" it instantly goes back to 500. That's where it seemed like I had the best luck was setting it aggressive and making it make small, fast adjustments to what I'll call "keep the pump spooled" (it's actually a priority valve, hence the quotes). As soon as it gets straight enough on the line for pressure to drop to standby, that's when it'll start steering more erratic. I'll attach a pic of the dead band cal summary with the p gain set to 11. The servo delay small signal is way high which goes right along with my theory about spooling the pump and no matter how high I ran the gain, I couldn't get that number down very far and my overshoot went up dramatically. I'm wondering if I've got an issue with the priority valve, I just don't know where to start. Should the standby be 500 or should it be higher like 7-800? Because it seems like that would make a huge difference. My other thought is its letting the load sense bleed off too fast for whatever reason. I also did check the pump and it appears fine. Stuck a gauge on a remote, deadheaded it, and it pegged the 3000 psi gauge. Deadheading said remote doesn't affect the gauge at the valve at all.


We have done some work with aftermarket autosteer valves. No expert though. Had some problems on a Versatile 435 and Case 7120 with the autosteer valves not getting along with the tractor hydraulic system. So we also purchased gauges, tees, hoses to observe what was happening on the load sense and pressure lines. The pressures and responses/actions you describe sound very normal and typical. Standby pressures are just that and I sure would not try to get them higher....500 psi seems plenty high. We landed up changing the load sense orifice in both valves to an adjustable needle valve to be able to make the system behave. The 435 especially needed a higher bleed off rate as it would not come off of high pressure once actuated.

Edited by WTW 11/16/2024 19:20
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