5.Ringkörper, Nuten, Kolbenoberfläche und Kolbenführungsfläche reinigen.

Part of step-by-step instructions on how to replace the seals in a so-called hydraulic plate.

I have never heard the part through which the piston moves called anything other than a cylinder. I would talk about cleaning the inside of the cylinder.
And though they refer here to the "Kolbenführungsfläche", I tend not to want to translate it into the very non-native sounding "piston guidance/guiding surface". The question is, if the target audience is non-native English speakers, would they understand what cylinder I was talking about?
I guess it's clear enough what is meant by "piston guiding surfaces" but I really would like to avoid that if at all possible. Just doesn't sound like normal English to me.
Eager to hear your comments/thoughts.