Hello, I’m having problems out of my Kobelco SK115SRDZ, the stick is weak (fast out-slow in), tracks seem weaker then they used to be, bucket curl out is fast curl in is slow, swing is good when you activate the stick while swinging though. It operates smooth, no loud whining noises pumps run cool. It seems as if this pump is not stroking properly. I have a pressure gauge kit but don’t know where to start testing, or what to test. One thing to note is this machine was always a fast strong machine, and I was on a job and notice the high speed travel stopped working and on the same job the machine got weak. Any help is appreciated, thanks.
If you post back with a serial number and year of manufacture off your machine then this can help other members to assist you with information that you may need for diagnosing the issue. You may be able to do a number of pressure checks using the machines display monitor if it has one. In the meantime try inspecting your hydraulic return filter and pilot filter for any indications of heavy metal contamination, going by your description I would not think you would see any issues with the filters but its always best to check anyway. Best regards