Brake regulator pressure valve mk3 except cooper s

All MK3 minis to 1978 except Cooper S MK3.Fitted mainly to cars with 3/4″ larger bore rear wheel cylinders.The correct regulator valve for all MK1/2 mini plus all Cooper S inc MK3 is 21A1774 where most models had 5/8″ bore rear wheel cylinders. The only difference however is in the poundage of the spring, weaker for this version to compensate for the change in wheel cylinder sizes.See MS72 for adjustable type. The stronger spring in 21A1774 is available as 27H6620.