Genuine AP Original Mk3 Cooper S and 1275GT servo is now supplied as this universal kit for single line brake systems. This kit replaces the servo originally sold on its own at no greater expense, but the brackets are universal for fitment to any vehicle and not the originals for Cooper S and 1275GT. Known as No6 type. The original mini type brackets as fitted to the Cooper S MK3 are available as
21A2254 or
MSSK007 kit and it is recommended to fit an in line valve available as
17H2646 to stop fuel contaminating the servo diaphragm. Boost ratio is 1.90-1 as per originals
A servo on drum brakes does wonders for stopping and if a future disc brake conversion is planned, a servo is a good first step. Air valve should be at bottom or 30-45 degrees up from bottom.
Beware of a copy now available at a very cheap price imported from China-