Not that familiar with excavators but starting a search for a 15-20 ton machine. My brother has a Case 210 and he was complaining about the way the hydraulic system is designed, if you try to do two functions at once it cuts the speed in half. ie: trying to track the machine an run the bucket at the same time. He blames it on the use of gear pumps instead of variable flow axial type pumps. Most any modern farm tractor uses closed center variable flow pumps which eliminates the problem for the most part. I ran across some info about a Volvo 210 or 220 that uses variable flow pumps. Does this alleviate the flow dividing slowdown problem? Are there other makes out there that use the variable flow pumps? Any opinions about a Volvo in the late '90's to early 2000's age?
I haven't heard of a gear type main pump in an excavator in many years. Case machines were or are still Sumitomo built the same as a Link-Belt and used Kawasaki or Uchida variable flow pumps, depending on the size of the machine, with open center hydraulic systems. All excavators will slow down when multiple functions are used at the same time. How much is more a factor of engine horsepower and pump set up and efficiency.
Going back a four decades, John Deere used closed center, variable flow pumps. Compared to everyone else's, it was SMOOTH! JD used a system much like your home's plumbing. Pressurized oil was dead ended at each control valve. Pressure was near constant, the pump sensed flow & increased volume as needed. Other systems used a downstream open center system. Oil flowed to one valve first, downstream valves were a lower priority. Open fully a priority valve, only feathering grooves allowed a small volume of oil to downstream valves. In an old Case, lift, swing, crowd & scoop simultaneously, it'd be slow. End other functions before ending the swing motion, swing takes off like a rocket. After years experience, I punched a hole in my house that way. In newer machines, each manufacturer has found a solution for that fault. My newest Case does NOT have that problem.