snoshoe

Foot and inch is pilot for relief valves. His foot was on pedal. Relief pressure is where ever pedal is. With pedal down valves are open. As he was letting pedal up it was trying to close valves against ever increasing pressure. Just another reason to use pedal only to start engine and as panic button. I did suggest capping lines first. That eliminates foot and inch. As for oil level. If it suddenly stopped from oil loss I'm pretty sure the puddle would have been obvious.

Could be either one. I'm betting forward high pressure relief valve. Cap off the two 1/4" lines coming out of center section. This removes all external valves from circuit so only control is S-R lever. If still nothing start digging for relief valve.

Just to clear up. While the pump is certainly suspect. The fact that it stopped all at once makes me suspect gear and key. Especially if when pump was replaced gear or nut were reused.

I seem to remember an oil passage in head gasket at that corner that could be a problem. That do look like exhaust though.

Before pulling clutch check pressure. There are number of external reasons for low pressure. Ranging from bent platform or linkage to debris under spool top.

At this point you know you have no pressure so gauges are useless. Pull mcv check for blown orings broken check valve as you go. Personally I suspect pump drive gear-key problem.

Cih partstore for diagram

I don't think the extra rpm will hurt the pump. I do believe you will find it hard to keep belt from slipping

Discharge and charge

Thats the worst thing you could do

Since youve been in there so much have you lost the sump check or its spring?

Right now I have more questions than answers. The normal way to test steering pressure is put guage in port on mcv and turn steering to stop. Read pressure with wheel held to stop. To check cylinder with wheels in above position. Remove hose from end of cylinder closest to piston. Again hold wheel to stop. Oil will either spray or dribble out of cylinder. If it sprays cylinder is problem. How do you remove hand pump from system and still restrict flow to build pressure? There could be a problem with flow divider that I have never seen with this unit. The spool or bore could be damaged in some way that would allow as much oil past spool as passes through orifice. A condition I have seen many times on other flow dividers but do not recall on this one. Also the spool could be stuck open. Again not common.

A 70 durometer nitile will stretch a lot easier than a 90 durometer viton but won't last near as long in a dynamic application like this. IH didn't give durometer or material. They used a class number. In this case I believe class 5.

I suggested this very thing earlier then discounted it. Afraid there would not be room to mount box far enough away to keep drive line angles down when raising and lowering. But then I really have no idea what this machine actually looks like.

You need fresh orings and more than one. You will probably need 3 or 4 to get one on. You can't just start it on small end and slip to groove. They don't streach that far. Need to be started in groove and worked over end. If they have been in stock to long they won't streach