How to Recondition Hydraulic Pistons

Cylinder hone will do if the scratches are minor and you are doing just a few. There are many sizes and types. The picture is of the most common. There are honing machines available.

Once upon a time ( some 15 years ago ) , I used to use inserts that were glued onto the original cylinder wall....took care of pits , scratches etc..........as I recall they were polished stainless steel tubes....seamless ( of course ) and somewhere between .002 and .005 in thickness.......they came with the glue...Worked like a champ for the 3000 psi "slow" cylinders that I was playing with......Never had a failure...Also note that if you overbore your cylinder that you will leak by the piston....

Don't recall the source of the inserts.......may have been McMaster Carr..........I was and am still a big fan of their catalog...........Also note that these were 3.5" cylinders....