Suggestions for testing valve seat in power steering valve assy?

[dcyrilc]

I have a JD 2240 tractor for which I'm rebuilding the power steering. I've had it posted in the repair section. http://www.tractorbynet.com/forums/parts-repairs/157149-2240-steering-rebuild.html Someone over there suggested that I pose the question in the hydraulics section for ideas on how to test the valve seats in the upper and lower valve assemblies for leakage while I have it apart. I have pix of everything including pertinate pages from the tech manual in the other post.

Anyone have any suggestions?

 

[dcyrilc]

Anyone?

 

[Barry Bowen]

This one is an easy answer, went down this road on my 301A 5 years ago, and there is no way to test them outside of the steering unit. (wasn't it fun getting those o rings down in the valve body) Put it together and start running it at fast idle, don't steer it, just let it sit there and run. Keep checking for where on the body that contains the valves it starts to warm up, should show up with in a shor time. The warm one will be the one that is leaking. Bad news, the valves cannot be rebuilt. Worse news the new ones are 300 or so. Which ever valve is leaking will become very clear. Run it long enough with the leak actually leaking and you can heat up the trans to the point that you cannot touch it! At least you do not have to remove the steering to replace those valves though, you can remove the wheel and the top nut and unscrew the entire valve shaft right out the top. You will be taking it out several times changing the shims on the new valve till you get it the way you want it. I had mine so lite the first time I put it together, one little push on the steering knob and it went all the way from one side to the other. Like every JD tractor nothing money cannot fix.