924Board.org

[isuras2]

If I were to do the 4 to 5-bolt conversion, do I need to get a new brake master cylinder? What about booster?
_________________
Rob
'80 931 (sold)
'80 924 NA (sold)
Former Omaha Crew

[gohim]

No, you don't have to replace the master cylinder or vacuum booster when you do the four wheel disc brake conversion, if you have a 1980 or later 924, as these are the same upgraded parts used by the 1980 924 and 931 cars that came from Porsche with the four wheel disc brakes standard or installed as an option.

1979 and earlier model year cars (without the four wheel disc brake option) came with smaller diameter master cylinder and vacuum brake booster. Even those cars do not require replacement as long as the driver understands that it will take more pedal force and travel to get the same amount of force on the brake pads that the cars with the larger master cylinder and vacuum booster generate with less pedal effort and travel.