Komatsu pc130f-7 2015 having problem desperately need help

hi guys just want to ask a few question,, i got 3 komatsu 130f-7 just recently bought 2nd hand as we were just testing the unit, its all well. Anyway when the unit finaly arrive at my location its started to have problem such as when there is load on the tracks i.e half covered in mud it would stop and not have any power to go up anymore, in the begining when the machine temp get hot it would become weak and cant even jack it self up, i have taken down the control valve change all the oring...

Komatsu pc130f-7 2015 having problem desperately need help

Komatsu pc130f-7 2015 having problem desperately need help