Brake master cylinder 1980-89 (yellow identity tag)

Genuine AP Lockheed boxed and made in UK. FRONT TO REAR master is the latest model dual master cylinders, which was introduced in 1985 with a stepped bore of 17.8 to 19mm to replace any previous master cylinders from September 1978 to 1988 when the built in servo type master cylinder was introduced. One of the notable features is the failure switch on the reservoir cap with a yellow identification tab. This replaces all the front to rear square type reservoir cylinders GMC173/198 and the GMC192/195. It should also be noted that this master cylinder has 2 different size metric unions, Top one is 10mm and the bottom one 12mm for the larger stepped bore size to the rear brakes. New pipe kits are required – for Left BAU5655MS AND Right hand drive cars is BAU5654 or in copper nickel BAU5654MS. The master cylinder repair kit is GRK1035. Late 1988 cars and those after had a built in servo, see GMC90376. Bottom piston does rear brakes – upper piston does front brakes.Some masters before this were the opposite with bottom doing front and top doing rear.Ensure the correct DOT4 or DOT5.1 brake fluid is used as these cylinders are not designed to use anything else such as Castrol SRF for racing or any mineral fluid.