Iv got a Komatsu Pc120lc that when trying to track it has low power and doesnt wanna move unless i barely pull back in the left boom stick. Also has low Hyd power when it gets hot. Any help would be appreciated. Thanks
Change hydraulic filters for starters. Check for any material in filters.
Filter was full of metal. Who rebuilds them good?
What Dash series machine do you have? What kind of metal did you find in the tank, steel, brass or cylinder packing?
Steel
Now I need to know the dash series.
Sorry pc120-6
How long have you had the machine and did this start all at once? How many hours are on the machine? Is the monitor panel flashing an alarm light and making a lot of noise? Do you know how to check for codes? There are a lot of things to check before pulling the pump. It is possible the metal in the filters could be from prior failures. There is a suction strainer in the hydraulic tank that you can pull and inspect. With that series of Komatsu there was also always the compensator valves that can be at fault.
I don't own the machine I'm the mechanic but don't work on a lot or excavators and most of the ones I do are Cats. They bought it with this problem and have ran it like this. They said after they run it for a couple hours it barely picks the bucket up. It doesn't make a lot of noise or wine at all. It also has low tracking power from start up but if you barely pull the the left stick it has all kinds of tracking power. I'm open to suggestions. I checked main pressure and it was fine but machine wasn't hot either
The fact that it will work hard when pulling back on the stick function kind of indicates a leaking compensator valve. If the pump were shot it wouldn't work no matter what you did. Possibly the piston and barrel assembly needs to be lapped but the system usually gets real hot if that is leaking by. This is a common issue on old Komatsu excavators and you don't find much if any help for it. Most people just start replacing compensator valves or swapping out the pump until the problem solves itself. One thing I can tell you is that the fix will not be cheap.
So what would you recommend doing?
I had a similar problem with a pw130-6 and it was the main relief valve located in the valve bank, after getting hot, it would let the pressure escape, dropping the working pressure of the machine.
There were at least three different types of main relief valves in the 120-6. I do remember changing a few of those out. What is the serial number of your machine? Some had the LS valve in the main relief, others had a separate LS valve.