Problems adapting a snow plow to a Kubota B7500

eddie48 · Jan 10, 2020

So, my son has a B7500 with loader. He found a snowplow on CR for free so, of course, it has to be fitted to the tractor. He did a nice job of designing and building all of the necessary hangers, etc to attach it to the tractor and everything fits just as it should. The snowplow has hydraulic angling. He got the appropriate hoses and connectors planning to remove the bucket from the loader arms and use the arms to raise and lower the plow with a chain in the normal plow chain position and then use the bucket tilt control on the loader to turn the plow from side to side. When he (and we) plug the hoses into the tractor bucket control valve, the plow will tilt one way and lock up. Reverse the hose connections and it will go the other way and lock up. We've tried about every combination of hookups we can think of. Changed fittings, hoses, changed the position of the fittings on the control valve...everything. It is always the same hose position on the control valve that won't let fluid return, but it doesn't happen when the bucket tilt cylinders are connected instead of the plow tilt cylinders. I'm scratching my head....Any ideas?

Fallon · Jan 10, 2020

Regen...

They dump full hydraulic pressure to both sides of the cylinder. The but end overpowers the rod end because there is less surface are due to the rod. That keeps things pressurized so it doesnt suck in air through worn seals as the bucket tips over and makes it dump faster as the rod fluid & pump fluid rushes into the but of the cylinder.

Works fine trading power for speed on double acting cylinders. If you try it with a pair of opposed double acting cylinders full pressure to each side cancels each other out.

Economy L machines (this was a Kubota right? Most machines are like this though) only have a 3 stage valve with regen only dump. The Grands have a 4 stage dump. A little to the right is a regen dump. All th he way to the right is a power dump like you'd expect.

You could swap boom lift & bucket curl for a quick but ugly fix. Will confuse your muscle memory & result in a fast but weak boom lift. Float wouldnt do you any good either. But it wont damage things.