Hi Guys, this is my first post, i have been reading this forum for years. really help to solve most of my issues with my excavator problems. and this time i decided to post because i havent found any solution for my problem in this forum and anywhere else. i Own excavator hire company, most my units are 20 Ton class excavator I have had this ongoing problem with some of my Komatsu PC200-7, me and my mechanics have been trying to find the cause of the problem for awhile (a year or so), with no luck. the problem is, after 1-2 hours of operation or after the engine is warm, the hydraulic is warm. it is very difficult for the excavator to turn left/right, but going forward and backward (with both track operate) are ok. the swing, boom, arm and bucket movements are normal. i changed the swivel joint seals, checked the motor travel parts inside, and even overhaul the main pumps. the problem still there your advice, input and feedback are appreciated thanks
Need a few facts before running down many paths at once. Serial number or year of manufacture is needed. How many hours on the clock? Have you checked pressures of the tracks when they are locked or running and trying turn? Have you done any cycle times on the boom, bucket and stick. Is this happening in the low travel speed or the high? Do you have any fault codes on the computer? Do you only have one operator on the machine or are there multiple people jumping in and out of the seat? Do all of them have the problem or does it follow one person? What is the condition of your undercarriage? Since the machine works otherwise I wouldn't suspect a fuel issue but you might check for stainers in the banjo bolts. Does this machine have the Komatsu engine or the Cummins clone?
I'd check the travel valves, both the pilot valves in the pedals, and the sections in the control valve
Can you check the unload pressure when its warm means after your excavator starts troubling you. If the unload pressure are below normal then the fault is most probably in the valve bank