I don't know how to draw in CAD to clearly explain my thoughts. This is the site where I obtained my John Deere 850 excavator, which is about the same size as what you are building.
You could either use these pictures as a guidline to improve your own track drives or inquire from Vario if they have a track drive component kit to sell to you?
http://www.vario-earthmovers.com/bau...70-teil-2.html
http://www.vario-earthmovers.com/bau...70-teil-3.html
http://www.vario-earthmovers.com/bau...70-teil-5.html
The servo automated rotary valves they use in their models work excellent too.
http://www.vario-earthmovers.com/bau...0-teil-10.html
Though your pump may be capable of producing 100bar, other components may rupture causing very serious injury. What are the limits of the nylon hose you use? You do have a pressure relief valve built into the system, correct? Safety first!