move prim up and down relative to parent prim?

I'm trying to make a simulation of a piston. If I have a flattened cylinder move up and down with a timer, I can achieve the basic effect. The cylinder will be contained in another longer cylinder w/ a partial alpha texture that gives the piston that metalic look.

My question here is how the up/down movement is gonna work once its linked into the larger object. If I rotate the piston, will the flattened cylinder keep moving in the original up/down axis, or will it automatically adjust itself based on its rotation?

Thanks,
Geuis

I got this working very well. So I now have a little object that looks like a piston, or pump. It works fine at any rotation and automatically adjusted itself.

However, when I linked the piston to another prim that I have as part of a suit I'm building, the little cylinder that moves back and for to simulate the piston started moving in relation to the new root prim instead of what was the root prim of the piston object.

I understand why this happens, but is there a way around it?