trainzkid88 wrote:

one issue is the factory rams are not made for over 1500psi and could fail but im sure pressure limiting valves could be included in the circuit for factory rams that are plumbed back to the tank so they relieve to storage instead of open air.
 

Not sure where you get your info from but anyway for the pump it is much simpler than adding relief valves to each circuit. Doesn't matter weather it is a modern pump or a thirty year old pump, it will only pump as much pressure as the main relief is set to. Unless you go to a piston pump you are not going to increase the pressure anyway and a piston pump needs a lot more than just an inlet and outlet. Getting a valve that includes a fourth position (Up, Down, Neutral and Float) for the blade could be quite expensive.If it is a sandwich style valve bank you may be able to add a bank into it for additional circuits. I recently did that for my Nephews D3. Some valves are available with relief valves for each circuit but again it adds expense.
I replaced a pump on my 1947 D6 with a pump made in 2012 and it performs the same as the original. Adapters are easy enough to make provided you have the room to fit them and can modify any piping easily.
Also if you use a pressure reducing valve instead of a pressure limiting valve you don't need a return line to tank.

the old rams were designed for 1200 psi WP most modern hydraulics are 5000psi WP hence why they are smaller and more compact for a given amount of work. and yes it wont be cheap hydraulics are rather expensive. who said anything a bout a piston pump. vane and gear pumps are capable of pressure too yes piston types are superior as true positive displacement. and its not just pressure its also flowrate. yes reducing valves would be a better solution. and yes simply rekitting the original with new parts would improve the greatly after all on these old girls they have been working for 40yrs or more its bound to wear particularly as its constant drive.

i see a lot of pictures of S.A tractors with the rear mounted hydraulic units, it is pretty easy to pick out the BE GE set ups but i see others similar but different set ups. what units were the most popular? since the SA tractors didn't have cylinders mounted on the tractor i would think as time or if needed a higher pressure or volume set was probably mfg? but there may not have been a need.