Komatsu mini excavator PC50 mr2 year 2007 low movement speed

[Ihabo]

Hello I recently purchased a komatsu pc50 mini excavator I noticed that all the movements are slow except for the tracks, blade and rotation are in perfect speed, most people told to adjust the control valve located at the main pump, does anyone knows how to fix this? Please help

 

[uffex]

Good day
Your post could well relate to poor pilot - servo pressure, I suggest you check this out first.
Kind regards
Uffex

 

[islander47]

Hello I recently purchased a komatsu pc50 mini excavator I noticed that all the movements are slow except for the tracks, blade and rotation are in perfect speed, most people told to adjust the control valve located at the main pump, does anyone knows how to fix this? Please help

Hello ! Did you found the problem ? I’ve got same excavator with very same problem. Pilot pressure is perfect. I found wear at the balls in the pump, I feel the rocker cam is hard to be actuated when using the machine

 

[heymccall]

I had similar issue on one in Keyser, a while back. Turns out that the screens on the pilot control inlets were partially plugged.
Worth a look since travel is good.

 

[islander47]

I havent found pilot pump filter at all on mine …. My actual opinion is that the swash plate (pump volume actuator) doesn’t move freely as should, then the pump doesn’t respond correctly from the Load sense LS given to it by the distributor

 

[Kobe Steel]

the pumps have common issues that start at around the 4000 to 5000 hour mark. Pump wears excessively in the cam sockets and the ball pivots as mentioned by islander47. Additionally the housing has a servo piston which tends to wear out in the bore of the housing. If you find these issues I would suggest replacing the pump regardless of the rotary group condition.

 

[islander47]

Ooh such qualified info ! Thank you so much the servo piston also have problems ? Very good info. I found my pump housing at rocker swash plate cam articulation have half balls inserted and strange weld job done around. But on the book it shows full balls, not half balls. Are the half balls sold as service kit such as weld inside ball housings and then you machine a cylindrical hole to fit the half balls, or are those half ball an improvement found in the newer pumps ?

 

[islander47]

Pictures of my pump

 

[Kobe Steel]

That is another variation of its design but I'm not sure if it was made specifically as a product improvement as these still had similar wear at the same amount of hours like the full ball type.(1/2 Ball type part number 708-1T-33432, Italian market PC50MR-2). Their is also 2 other variations that I know of, one for machines equipped with air conditioning and one with no A/C. These pumps can be found in various other machines from excavators(main pumps) to dozers and wheel loaders(Cooling Fan pumps)

 

[islander47]

I ´m purchasing a new pump housing in China, that holds the half balls. Thank you for your very valuable info return !

On the market I can see plenty of those pumps new and used refurbished, that means lots of people have problems with them I guess. But why almost nobody communicate about this … a chance you are here.