Komatsu Pc200-8 weak arm/stick out

[GTpesado]

Hello friends
I have a pc 200-8. Serial num. Kmtpc180h02355178
Stick out is weak and mostly slow. On monitor and verified with gauges. Both pumps put out 37.0 mpa . Stick in shows more like 31mpa but stick out only shows 26 mpa
Things I did
Swapped pressure compensators
Swapped the boom and stick anti drift and quick release valves
Checked the suction valve on the stick section
Swapped the pilot hoses on the joy stick and the problem stayed with the stick in funtion
?????

 

[Vetech63]

Have you confirmed the cylinder seals are good?

 

[GTpesado]

the seals have been replaced about a year ago....and the stick does not fall or drift at all. If the oil in the head side is leaking pass the seals to the botom side that fast should there not be terrible drift on the stick cylinder?

 

[coalrulz]

Not sure that I have seen a 200LC-8 with a boom quick return valve. Are you sure issue is not in arm quick return valve?

 

[GTpesado]

Also when operating the stick and you touch another function the stick jerks
I swapped 8 and 9. It calls it the arm and boom drift prevention, I thought that was the same as the quick return, mabey it’s a different valve

 

[coalrulz]

Which specific functions when operated cause the stick to jerk?

 

[GTpesado]

Which specific functions when operated cause the stick to jerk?

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boom or bucket…..it makes the stick really jerk when you as much as touch the other functions even before they start to move much. If you just touch the joystick it like cuts the pilot pressure to the stick for like a split second thus the jerk

 

[GTpesado]

boom or bucket…..it makes the stick really jerk when you as much as touch the other functions even before they start to move much. If you just touch the joystick it like cuts the pilot pressure to the stick for like a split second thus the jerk

Ok I see the quick return is on the other side of the section

 

[GTpesado]

I forgot to mention that cold you don’t notice it near as much, mabey a little slow but as it warms up it slowly gets worse. With about half an hr of operating, stick out is very slow….takes about 10 seconds to get the whole way out

 

[GTpesado]

If the output of the pump is low. Is it not a problem on the signal side, or LS? But only for the stick. Would the quick return afect it that way?