UK Car Repair: MG midget frt disc brakes, disc brakes, mg midget

Question
I have taken the frt. calipers off to rebuild them. I have them all apart but am curious about the piston. Where the piston touches the shoe, one side of the piston is relieved, like a small section has been shaved away. I just want to know what the purpose of this is and how critical the positioning is. Thanks in advance.

Answer
There is no reason given (I looked, a lot) but with an unsurmountable knowledge I'll try and think one up.






the chamfered edge goes to the back (rear) of the brake shoe.
the idea is to have more pressure at the front of the shoe and less at the back, it's anti-squeal.




the MG's never had any brake "issues" as far as I'm concerned... I think it's just modern(ish)  anti squeal,

Modern brake pads have no asbestos in.. and they squeal.

The cutout is to provide extra anti squeal for the (because of) asbestos-free pads




      --->Put the cutout side of the piston facing the rear of the car, all should be well<---