Brake Hydraulics Identification Chart
| Description | Master cylinder | Bore size | Front caliper /cylinder | Bore/disc | Rear wheel cylinder | Bore size | Cast No. | Regulator valve |
|---|---|---|---|---|---|---|---|---|
| Dry suspension Mini 1959 to chassis number A2S7 359770 to 1962 | GMC153 | .750" | GWC101 | .9375" | GWC1102 | .750" | 12 | 21A1774 |
| Dry suspension Mini from chassis number A2S7 359771 1962-67 | GMC102 use GMC171 | .70" | GWC101 | .9375" | GWC1101 | .625" | 10 | 21A1174 |
| All hydrolastic Mini MK1 Minis from September 1964 on | GMC102 use GMC171 | .70" | GWC102/3 | .8125" | GWC1101 | .625" | 10 | 21A1774 |
| MK2 Mini and derivatives 1967-75 | GMC102 use GMC171 | .70" | GWC126/7 | .9375" | GWC1102 | .75" | 12 | 21A1774 |
| MK3 Mini October 1968 on and derivatives, single line to 1977 | GMC171 | .70" | GWC 126/7 | .9375" | GWC1102 | .75" | 12 | 21A2031 |
|
997 Cooper to chassis number
C-A2S7 213829 to Feb 1962 with 21⁄8" padsK-A2S4 213550 with 21A655 brake booster |
GMC103 Use GMC153 |
.75" | 27H4652 27H4653 |
7" disc GBP101 pad |
GWC1102 | .75" | 12 | 21A1774 |
|
997 Cooper
C-A2S7 213829-382831 Feb 1962 to March 1963 with 21⁄8" padsM-AS4 213551-382183 |
GMC104 Use GMC171 |
.70" | 27H4652 27H4653 |
7" disc GBP101 pad |
GWC 1102 | .75" | 12 | 21A1774 |
|
997 Cooper dry C-A2S7 382832 March 1963 on with 2 3⁄8"
pads998 Cooper hydrolastic K-A2S4 382184 on |
GMC171 was GMC105 |
.70" .625" |
27H4654 27H4655 |
7" disc GBP102 pad |
GWC1101 | .625" | 10 | 21A1774 |
| Cooper'S' MK1/2 with servo 21A1293 | GMC172 | .70" | 27H4656/7 | 7.5" disc | GWC1101 | .625" | 10 | 21A1774 |
| Cooper'S' MK3 1275GT with servo 13H7939 10" wheel | GMC172 | .70" | 27H4656/7 | 7.5" disc | GWC1101 | .625" | 10 | 21A1774 |
| 1275GT Single line brakes chassis number 19416-21569A 1974-76 | GMC172 | .70" | GBC138/141 | 8.4" disc | GWC1129 | .6875" | 11 | 21A1774 |
| 1275GT Diagonal split chassis number 19416-21569 on 1974-76 | GMC160 | .70" | GBC138/141 | 8.4" disc | GWC1129 | .6875" | 11 | None |
| 1275GT Single line brakes chassis number 21570A on 1976-77 | GMC172 | .70" | GBC138/141 | 8.4" disc | GWC1126 | .500" | 8 | 21A1774 |
| 1275GT Diagonal split chassis number 30001 on 1977-78 (Metric pipe unions) | GMC167 | .70" (17.5mm) | GBC138/141 | 8.4" disc | GWC1126 | .500" | 8 | None |
| 1275GT Front to rear tandem 1978 on (Metric pipe unions) | GMC227 | .70" | GBC138/141 | 8.4" disc | GWC1102 | .750" | 12 | FAM7821 |
|
850/998 Diagonal split Imperial union Master (Europe)
(not UK) 1976-77 Japan/Norway |
GMC160 GMC160 |
.70" .70" |
GWC126/7 GWC126/7 |
.9375" .9375" |
GWC1126 GWC1134 |
.500" .5625" |
8 6 |
4 way switch 13H5905 |
| 850/998/1100 Front to rear (Belgium Netherlands and Luxemburg countries) 1974-75 (Belgium built) |
GMC159 | .70" | GWC 126/7 | .9375" | GWC1102 | .750" | 12 | 4 way switch 13H5905 |
| 850/998 Diagonal split except van/pick up 1977-78 (1976-79 Europe) Metric | GMC167 | .70" (17.5mm) | GWC 126/7 | .9375" | GWC1131 | .5625" | 9 | None |
| 850/998 Front to rear October 1978 on (1980-84 Europe) was GMC173 Imperial | GMC227 | .70-.75" (17.8-19mm) | GWC126/7 | .9375" | GWC1102 | .750" | 12 | FAM7821 |
| Mini van/pick up diagonal split 1977 on (Metric pipe unions) | GMC167 | .70" (17.5mm) | GWC 126/7 | .9375" | GWC 1102 | .750" | 12 | None |
| 998 Mini front to rear 1984 on (Metric pipe unions) - stepped bore | GMC227 | .70-.75" (17.8-19mm) | GBC138/141 | 8.4" disc | GWC1102 | .750" | 12 | FAM7821 |
| Innocenti (1275GT not UK) Front to rear 10" wheel with AXE244 servo | GMC159 | .70" | 27H4656/7 | 7 1/2" disc | GWC1129 | .6875" | 11 | 4 way switch 13H5905 |
| 998/1300 Latest 1990 Mini with built in servo GSM119. was GMC242 | GMC90376 | .8125" (20.6mm) | GBC138/141 | 8.4" disc | GWC1102 | .750" | 12 | FAM7821 |
| ERA Turbo with built in servo GSM119. was GMC242 | GMC90376 | .8125" (20.6mm) | GBC131/2 | 8.4" vented | GWC1131 | .5625 | 9 | None |