Ferrari 308 seized front brake calliper

So I was out driving with the SuperCarDriver guys the other week in my Ferrari Dino 308 GT4 starting pulling to the right (drivers side UK) under braking. I've never really looked at the front brake callipers so I suspect it is time for a rebuild.

The original brake callipers on the 308 are made by ATE and are in fact the same as fitted to the late 1970's Porsche 911 which means that rebuild kits and in fact new callipers and pistons are easy to come by.


So I pulled the left hand calliper pads to take a look and sure enough one of the pistons was seized. So definitely time for a rebuild.

Whilst the hydraulics were still connected and with the pads removed I used the brake pedal to push the pistons out as far as they would go as getting seized ones out once the callipers is removed can be hard.




Next thing was to remove the calliper and remove the pistons. It's normal to use compressed air to pump the pistons out of a removed calliper - clamp the one you don't want to come out first.

This worked finally and the seized outer piston came out. A bit of air also removed the free inner piston to reveal the cause of the seizure - rust of course.



You can see that there is no rust inside the cylinder area but you can see the rust on the thin section after the groove where the hydraulic seal goes. I used a dremel type drill to remove this surface rust - being careful not to mark the inner cylinder area. I also cleaned out the seal groove which showed some signs of rust.


Clean up and rebuild in the next post :)