Brake piston slightly proud (dent) - usable?

[bruce.g.cameron]

This is a rebuilt Beck/Arnley brake, which I thought was supposed to be good quality.

However, as you can see, someone beat on the piston in the past. Do you think this would be enough to put the pad out of square?

The rotors I'm replacing had a solid 3/4in (radially) of rust, where the pad wasn't contacting. I found the pads caved in at the top (pretty thin but not down to metal), and then found calipers on the car has some rust on the pushing surface of the piston, so I don't want to repeat the same issue!

[bruce.g.cameron]

Alternately, I could file it down so it isn't proud, but would then presumably have to paint the filed part to prevent rust?

[Rogviler]

If it were my car I would just file it flat. I don't think they have any kind of coating anyway so I wouldn't worry about rust. If it did it would wear off anyway, and you'll most likely be putting brake grease on it too.

-Rog

[t walgamuth]

Originally Posted by Rogviler

If it were my car I would just file it flat. I don't think they have any kind of coating anyway so I wouldn't worry about rust. If it did it would wear off anyway, and you'll most likely be putting brake grease on it too.

-Rog

agreed.

[bruce.g.cameron]

Will do!

Thanks gentlemen.

[torsionbar]

Assuming these are steel, yes absolutely file it as recommended.

If the pistons are anodized aluminum however, like they are on the Brembos, then the piston must be replaced. Once the anodizing is compromised, corrosion will spread quickly and it will leak at the seal.

[t walgamuth]

Prolly not too many Brembos on the old 123 cars.