JD F735 zero turn hydraulics

Let's see if we can drum up some replies for you in Pit Row.

I got the service manual online which helps with troubleshooting. Also the hydraulic oil was way low. And it looks like I have a leak in the steering control valve. I did manage to get the steering to work sluggishly. I can’t find any rebuild kits for the hydraulics for this tractor, they really don’t want you to fix anything. Apparently there is two sides to this hydro pump, one side runs the hydrostatic motor for drive and the other is a charge pump for steering and deck lift cylinder. To be continued.

The charge pump ensures that the hydro pump has adequate fluid first. Any flow left over goes to the power steering and implement lift.

A low fluid level can leave the charge pump with just enough fluid to supply the hydro and nothing else. It's not likely, but under the right circumstances, it is definitely possible.

Take the numbers off of the power steering orbital valve and take them to you local hydraulics shop. They should be able to get the repair kit in short order, if they don't have it in stock. GTs aren't the only machines that use those valves.

Keep looking. The steering valves usually last for several thousand hours before creating a fault. Taking one apart is not a problem. Putting it back together successfully apparently can be problematic. I've never had occasion to try, but I have read about a couple of others who have over the years..