The first thing you need to install is the factory remote outlet that went from the pump to a female quick coupler under the seat. You could probably gather the items up from a salvage yard or two. The next item to get is the 4 way valve AC offered to use on the D series prior to the D17 series 4. You can get the valve on this site. Click on the 'parts' word, click on Allis Chalmers, click on hydraulic system, it is th valve shown. The next thing is to plumb a return line into the bottom of the reservoir case by removing the drain plug and fashion from there. You could tee in an extra hydraulic reservoir at this point but don't get its full level above the full level of the tractor resevoir. If you did not need a lot of extra fluid capacity you could use oversized return lines and let them be the 'reservoir'. In any event the original AC system was 3500 psi and you can blow a light weight cylinder. I setup a 4 way valve using Prince components from the Northern Tool folks. The inlet section of the valve is a pressure reducing section.
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