Kobelco Excavator with Engine Bog Under Load

My excavator would idle great for long periods without issues but then intermittently bog down under a small load that was well within it's capacity.
Looked everywhere for fuel related issues and finally found the plugged up screen. Forums talk about one inline strainer but my machine had two. one at the lift pump inlet and the other at the water separator. no one talks about the water separator screen.
Cleaned the screen and big issues went away.

[@destinationom]

Wow! Thank you! I have been struggling changing my fuel filters and had even emptied my tank and cleaned it but never knew about this. I'll have to get out there tomorrow when it's light out and check this! UPDATE!! THAT WAS IT!!! I had flushed my tank and changed the fuel filters many times and had NO IDEA this little filter was on the in line to the seperator!! Took it apart and cleaned with carburetor cleaner and now works like brand new!!! I have a 135c John Deere with Isuzu engine. Where do you buy these small replacement filters, mine was still rusty and surely time for a new one but IT RUNS GREAT!! THANK YOU!!!

[@constructionduru5195]

I'd bet your tank is loaded with rust and gunk... just did the tank on my Kobelco a week or 2 ago...mine was so bad I used a shopvac to get all the crap out! Have you ever tried adjusting your hydraulic pump? Trying to figure out how to do it but there isn't much info. GL with your tank!

[@tubme574]

I haven't had to adjust the pump yet.

[@tubme574]

I do have a manual with instructions.

[@shhs1791]

My Kubota is losing hydraulics.. (doesn't release oil) ... If I lift something high.. the arm with the bucket will go down if I don't move the control levers.. What could it be ??

[@Offical478Outdoors]

Cylinders need repacking. They leaking internaly. Just regular wear over time is all.