I have an old Cat 320, along with several other Cat excavators. It is a 9KK model circa 2000. The excavator is a bit slower than the others.I was wondering if the hydraulic pump can be adjusted a bit to increase speed.
You need a hydraulic tune-up.First check the motor at full load with the pump control exceeded.Then calibrate the speed dial and PRV valve.Then dig in and see if it improves.If it’s still slow, put a couple of pressure gauges on the NFC lines on the pump to make sure the pressure is dropping to around 100 PSI when working.If they do not drop when the circuits are used, the slow return check valve may be backing up and needs to be tightened.It is in the same aluminum valve body as the refrigerator bypass valve. So all pressure relief valves are up to specification