As fitted to Mk3 classic Minis up to 1978 (except Cooper S); regulates the flow of fluid to the rear brakes to adjust their application. While the front brakes do most of the work during braking, this valve controls the rears and helps prevent loss of control if braking while turning. This valve is primarily found on UK/Euro-spec Minis, and differs from the 13H7757 inertial valve used on Canadian models.
If your Mini has been upgraded from original drum brakes to Cooper S disc brakes, you will normally want to also install Cooper S-sized wheel cylinders in the rear and fit the 21A1774 version of this valve. The 21A2031 valve can be converted to 21A1774 specification by replacing the original internal spring with 27H6620 spring.
9/1/2021 2:00:00 AM