Discussion in 'XJ Technical Chat' started by jag3, Jul 30, 2021.
I had old FJ 600 calipers and the piston protruded slightly like the one in the picture.
So, the back of the bore is not a raw casting surface but is also machined? Didn't know that for sure.
The entire bore is machined out of the casting (there may be a hole there already, but it will be undersized), along with the other passages. Even the outside of the casting is machined where the mould line is, and for the mounting and sliding surfaces. Raw castings are almost never good enough to use without being machined first.