hi friends, i just recently registered as a member.. this site contains so much info regarding heavy equipments.. it is very helpful.. I'm having problems with my pc40 excavators.. the arm functions are slow... boom up, extension, arm articulation and bucket functions.. we have changed all filters and hydraulic oil.. swing, dozer and travel functions are great, very responsive.. we are having trouble diagnosing the problem.. any suggestions? regards, mykesr8
Maybe a worn pump?
The swing, travel and Dozer functions are working great.. We doubt it if it's the main pump..
What is the pilot pressure to the spool end caps? Pressure differential in the good circuits to bad while working? Pressure at the pumps in stalled condition?
The swing and dozer functions run off a different pump. You need to check to see which kinds of pumps are in this machine. As I recall some had gear pumps and an open center hydraulic system while others have piston pumps and a closed center load sensing system. In any case you will have to install gauges in all the pump outlet circuits and analyze what you observe to be able to troubleshoot the problem.
I agree with John. Most machines have more than one pump. U may want to check pressures
Hi mike, We will check pressure levels, thanks for advice Hi john c., Yes, this one has a gear type pump.. Which like you said will have a open center hydraulic system, We will start from there.. Very helpful.. We'll check it.. I will update upon progress.. Thank guys