Hydraulic steering/3-point hitch problem

Maybe you can help me fix a hydraulic problem on my 1966 John Deere JD 300? The previous owner has rigged a manual hydraulic flow/priority valve which has to be adjusted to proportionally divert fluid to either the power steering or the 3-point hitch as the demand would dictate.(see pict in attached link or gallery>parts and pieces>jd300 hydraulic hack) I�m not sure if there is a priority valve that has failed or if it�s just the leaky old main pump not able to service them both at once, but it�s a major hassle to operate this way. I need an aftermarket main hydraulic pump or even a rebuild kit but can�t seem to find a mfg except for my JD dealer at $1400 for the pump in a box. Ouch! Any links/contacts/tips for rebuilding it or checking the priority valve? Thanks again. Please respond with detail or e-mail me at [email protected]
Thanks, Michael

I can't see under the step to see if it has a pressure control valve. I doubt that the transmission case is drilled for the valve if it is the old serial no.

I think the thing to do is, check the serial no. try to determine if it has the pressure control valve, try to determine which steering column you have and see if any oil lines under the hood near the front of the engine have been modified.

There are a lot of places to get rebuilt pumps, A@I, Abalene Machine, Worthington Ag Parts, and several other places. Be sure you need it before buying.