Hey I'm Lars I'm on my 3th Kobelco sk350 lc that I one's and daily drive! I have a mysterious problem with vibration in my joystick. I haven't find anyone in Sweden howe has heard about it before, so I trying here ! Machine whas delivered in August last year, brad new! after the first day I felt that my hands whas stum and out of feeling! day nr 2 legs back,arms start reaktion..... well we start to trubbel shooting where the vibration comes from and when they start! at morning when I start the machine everything's works fine, around one or one and a half, hours (depending on temperature outside ) I have my oil temp up in 33 celsius and a i start to feeling the vibrations and when I retching 37 celsius, then I can drive it any more because my hands hurts. we have controlled all pressure, they sems to be ok, we have try put servo pressure up and down, non reaktion... chenge servopump and even try to change the extra hydraulic pump !! but it is still there! Help../ Lars
If joysticks are PPC hydraulic valve, I suggest you test the pilot pressure upstream and downstream the joystick with bourdon tube pressure gauge using short hose (old school gauge) looking for any ripple. In other words, if the gauge needle is shaking or not