[johnny88]

Look at the attached photos. You need to remove 3 screws that secure the hydraulic pump, and 1 screw that secures the servo/valve frame. All the screws have rubber O-Rings that I presume is to keep hydraulic fluid leaking out the bottom of the body. Don't disconnect any of the hydraulic lines - not necessary. 2 screws secure each servo. I highly recommend replacing all 4 at once. Once my 4200XL was acting crazy - the tracks would go, the turret would turn, hydraulics would move at the same time even though I was not inputting any of it - it was a bad servo that electronically was making the machine out of control.