Komatsu Excavator PC400LC-7 Low Hydraulic Power

[TheRagnarok]

I am helping someone diagnose an excavator that he was loaned to help with a big job. I do not know much about them other than they are hydraulic and pretty complicated. The machine runs great and will rev up when you start trying to work it. It just does not have much power and will barely will lift the tracks when you push down. I pulled the hydraulic tank screen and there was a good bit of dirt and lots of brass shavings (the size of glitter). I'm thinking that the pump is on its way out but I not 100%. The display for the computer is on order as it got too much sun and peeled apart. So I cannot really see any pressures or readings. I also do not have the tools to read hydraulic pressures.

 

[funwithfuel]

Did you drain the hydraulic tank prior to pulling the sump strainer? Did you inspect the return filter and the well that it sits in? Is the bypass and backup strainer still in good shape sitting on the return filter? The fact that you went panning for gold and found some is a bad sign. Could be an old repair that was never properly cleaned, that's where the filter well will tell the tale. Good luck

 

[TheRagnarok]

Alright, I didn't drain the tank when I pulled the strainer. Everything built up on the strainer was inside of the ridges. Cleaned it and put it back in.
Just checked the return element and it was super clean, no discoloration and no metal flakes. And the bypass strainer was very clean but did have a 1/4" gash right at the top side.
I have a set of pressure gauges ordered that go up to 10k psi.