Uploaded June 2021 | Updated September 2026, 2 weeks ago
How a brake master cylinder (MC) works. This video shows an Ate (Continental Teves (ATE)) brand master brake cylinder from a Mini Cooper (2006 JCW R53), part number 03.2122-1824.3 (non-DSC part number 03.2122-1853.3). It is a tandem style MC with two pressure volumes within a single cylinder providing two circuits of brake fluid pressure to the ABS unit and ultimately the brake calipers. Ate brand MCs are used in many other makes such as BMW, Audi, and VW. The MC is activated via the brake pedal, where the pedal pushes a shaft in the brake booster which in turn moves the MC shaft. Mushy or soft brakes are sometimes due to air being trapped in the master cylinder or seals within the MC allowing fluid to leak past them.
Video shows a cut-away, a simple computer animation, and a crude idea of how to disassemble and assemble the MC.
Technical information:
Diameter 22.2 mm
Number of connectors 3
Thread Size M12x1
Length 1 42.1 mm
Length 2 109.3 mm
FCP Euro part: fcpeuro.com/products/mini-brake-master-cylinder-cooper-0321221824302
Ate: ate-brakes.com/products/hydraulic-parts/master-brake-cylinder
Mini brakes: pmmonline.co.uk/technical/the-intricacies-of-the-mini-braking-system
How a brake master cylinder (MC) works. This video shows an Ate (Continental Teves (ATE)) brand master brake cylinder from a Mini Cooper (2006 JCW R53), part number 03.2122-1824.3 (non-DSC part number 03.2122-1853.3). It is a tandem style MC with two pressure volumes within a single cylinder providing two circuits of brake fluid pressure to the ABS unit and ultimately the brake calipers. Ate brand MCs are used in many other makes such as BMW, Audi, and VW. The MC is activated via the brake pedal, where the pedal pushes a shaft in the brake booster which in turn moves the MC shaft. Mushy or soft brakes are sometimes due to air being trapped in the master cylinder or seals within the MC allowing fluid to leak past them.
Video shows a cut-away, a simple computer animation, and a crude idea of how to disassemble and assemble the MC.
Technical information:
Diameter 22.2 mm
Number of connectors 3
Thread Size M12x1
Length 1 42.1 mm
Length 2 109.3 mm
FCP Euro part: fcpeuro.com/products/mini-brake-master-cylinder-cooper-0321221824302
Ate: ate-brakes.com/products/hydraulic-parts/master-brake-cylinder
Mini brakes: pmmonline.co.uk/technical/the-intricacies-of-the-mini-braking-system
