685, 684, 674 hydraulic plumbing

right now if my flow chart is correct, the mower valve is plumbed so that it returns working pressure to the hydraulic system in neutral, but none when actuated, it dumps the return oil to tank. have not put many hours on it, but my dad was complaining of steering loss occaisionally, possibly when operating the mower lift valve. Since the complaint, i changed the filter, but weather was not cooperative to try it out. At any rate, I just don't like the crude plumbing and the hoses extra vulnerable.

let me know if i'm on the right track, and i'll tell/ask more
thanks
karl f

To work on this the complete platform will have to be lifted on the 3pt hitch control side. This is not as big a job as it sounds but have to lift it straight up until it clears all the control levers and then block up with some wood.
It is a two person job unless you have an engine hoist or other like equipment.

Hope this is as clear as hydraulic oil.
JimB

back to illustration 8-380: the current set up has the supply hose at the mcv where 36 should be, and the return work oil hose to 36 (cylinder return is dumped to the filler plug). i don't like that, and want to mimic the normal setup as much as possible until we are done using it as a brush mowing rig and want to convert it to a regular tractor. interestingly enough, it has a working rockshaft with liftarms and all the flow and draft control valves. that mower company's modern tractor/mower combos are no longer stripped down like that, and allow the tractor to be utilized in other ways.

i know the serial number is after 18001, since the castings for the non 4x4 access covers match that newer design. the correct valves for that ser. no actually would have power beyond built into the attaching plate. but i'm sure older parts will fit as long as they are swapped as assemblies vs components.

thanks for your help
karl f

i should be able to open where that fitting and #37 connect, and supply the external valve's input there, and put the pressure return to #37. if that is correct, i still have a question.
should the cylinder return from the external valve be dumped to tank or the fitting where pipe 38/18 is attached to #37?

thanks. karl f

Hope this helps
JimB