hydraulic piston scoring

[JoeS52]

I'm replacing the seals, bucket cylinder for my newly aquired BCat 331 excavator. Scoring on the piston, anyone experience this and if so did you replace seals and roll on ?
What was the result ?
Thanks in advance

 

[tech.35058]

Use a mill file to make sure nothing "sticks up" on the piston diameter. check the sides of the seal ring groove to remove any burrs dragged in from the piston scoring. check the cylinder bore for scoring. ( light scoring can be improved with a hone or a "flap wheel". or just ignored). be sure to check the rod for scoring. if any is found, check the rod for straightness. If straight, raised scratches can be "improved" by wrapping an emory polishing strip around it & "shoe shining" it. Be sure everything is clean going back together. From the photos, all should give good service.

 

[JoeS52]

No scoring on the piston rod, I have emory, will do that and thank you again.

 

[PistonPete]

My buddy had the same scoring on his 430. Just swapping seals won't last and the rough piston chews them up in weeks. We honed the bore, got a new rod from the dealer, and used a FridayParts seal kit. Held up fine so far.