mini brake data

When working on your brakes, ensure that the brake pads, shoes and hydraulic cylinders used match the specifications given below.

Over the years, many changes were made to Mini brake configurations. The manufacturers tinkered with the master cylinders and rear brake balance valve, and rear shoes and cylinders on many occassions, and did not necessarily write these changes into the official service manuals. As specific data on change points is found it will be added to this page.

Hydraulic system layout diagrams will be added as time permits.

All disc-brake hubs are compatible with all disc-brake configurations, and both types of drum brakes share the same hubs.

Mini Mk1, pre-1964 (to Chassis Nos. 296256 and 638878)

Type Lockheed hydraulic drum brakes, single leading shoe all-round.
   
Front/Rear  
Type Drum, 7 in (177.8 cm) diameter
Lining Material Don 202
Lining Dimensions 6.75 in x 1.25 in (17.14 cm x 3.17 cm)
Lining Area 33.75 sq. in (217.7 cm2)
Master Cylinder bore 3/4 in (19.05 mm)
Front hub bearings Ball bearing
Wheel cylinder bore (front) 13/16 in (20.64 mm)
Wheel cylinder bore (rear) 5/8 in (15.87 mm)

 

Mini 1964-1985, except: Cooper and Cooper S, 1275GT 1974-on and Moke Californian

Type Lockheed hydraulic drum brakes, tandem hydraulic lines from 1976.
   
Front/Rear  
Lining dimensions 6.75 x 1.5 in (17.4 x 3.18cm)/6.75 x 1.25 in
Lining area (from 1965 manual) 40.5 sq. in (261.29 cm2)
Lining area per front (1976 manual) 20.5 sq in (132.3 cm2)
Lining area per rear wheel (rear, 1976 manual) 17.1 sq in (110.3 cm2)
Lining material Don 202
Front hub bearings Ball bearing
Master cylinder bore 0.7 in (17.78 mm)
Wheel cylinder bore, front 15/16 in (23.81 mm)
Wheel cylinder bore, rear 3/4 in (19.05 mm)

 

Mini Cooper 997 and 998cc

Type Lockheed hydraulic brakes, front disc/rear drum.
   
Front  
Type Disc, 7 in (177.8 cm) diameter
Pad material Mintex M78 (red/green/red/green/red)
Pad area (total) 13.8 sq in (89 cm2)
Swept area (total) 101 sq in (651.5 cm2)
Minimum pad thickness 1/16 in (1.6mm)
Front hub bearings Timken taper roller
   
Rear  
Drum size 7 in (17.8cm diameter), inbuilt spacer
Lining dimensions 6.75 x 1.25 in
Lining area total 40.5 sq. in (261.29 cm2)
Lining material Don 202

Cooper 997cc calipers from C-A2S7 382832 (RHD)/C-A2S7 382843 (LHD) and K-A2S4 382183 (RHD)/K-A2S4 379926, March 1963, were redesigned and use different brake pads; these calipers and pads are not interchangeable. Also at this time an uprated (330 psi) rear brake pressure limiter, and improved master cylinder, brake shoes, brake backplates and rear wheel cylinders were fitted, though no details have yet been found. The later calipers are often referred to as "Cooper 998cc" or "Cooper Mk2" type, despite being fitted to some 997cc Coopers.

 

Mini Cooper S Mk1-3,1275GT to 1974, Innocenti Cooper 998 and 1300

Type Lockheed hydraulic brakes with vacuum servo, front disc/rear drum.
Servo Type (Mk1, 2) Lockheed type 5 1/2 (5 1/2 in)
Servo Type (Mk3) Lockheed type 6
Servo Type (1275GT) None, except Lockheed type 6 from 1972 to 1974.
Servo Type (Innocenti Cooper, late) Bonaldi
   
Front  
Type Disc, 7 1/2 in diameter
Pads (to Commission No. 000573A) Ferodo DA6
Pads (to Commission No. 000574A) Mintex M78 (red/green/red/green/red)
Pad area (total) 17.3 sq in (111.4 cm2)
Front swept area (total) 122 sq in (787 cm2)
Minimum pad thickness 1/16 in (1.6mm)
Front hub bearings Timken taper roller
   
Rear  
Drum size 7 in (17.8cm diameter), inbuilt spacer
Lining dimensions 6.75 x 1.25 in
Lining area total 40.5 sq. in (261.29 cm2)
Lining material Don 202
Wheel cylinder diameter 0.75 in (19.05 mm)

 

Mini 1275GT 1974-on, all Minis 1985-on, Moke Californian

Type Lockheed hydraulic brakes with vacuum servo, front disc/rear drum, tandem hydralic lines.
Servo Type (1989 on) Servo fitted, type unknown.
Master Cylinder Same spec as Mini 850/1000 tandem drum brake cylinder.
   
Front  
Type Disc, 8.4 in diameter non-vented.
Pads Mintex M121 (LDB 751)
Pad area (total) 16.6 sq in (107 cm2)
Front swept area (total) 134.46 sq in (864.5 cm2)
Minimum pad thickness 1/16 in (1.6mm)
Front hub bearings Timken taper roller
   
Rear  
Drum size 7 in (17.8cm diameter), inbuilt spacer
Lining dimensions 6.75 x 1.25 in
Lining area total 40.5 sq. in (261.29 cm2)
Lining material Don 202
Wheel cylinder diameter 0.5 in (12.7 mm)

Mini ERA Turbo

I am presently trying to find specific details. The ERA Turbo was fitted with the Metro vented 4-pot 8.4 inch front disc setup, possibly on Mini hubs. The hydraulic system was redesigned to make use of the dual fluid connections on the Metro calipers.