For 1990-2009 cars only
Brake System Specifications for GMC Truck GMC P42 Commercial Chassis 1999
System | Master Cylinder Diameter | Front Disc Brakes | Rear Drum Brakes | Rear Disc Brakes | Brake Assist |
|---|---|---|---|---|---|
JB7 | 31.8 mm | 319 x 39.3 mm | 331.5 x 63.8 mm | -- | Hydraulic Hydro-Boost |
1.25 in | 12.50 x 1.54 in | 13.00 x 2.50 in | -- | ||
JB8 | 31.8 mm | 319 x 39.3 mm | 331.5 x 63.8 mm | -- | Hydraulic Hydro-Boost |
1.25 in | 12.50 x 1.54 in | 13.00 x 2.50 in | -- | ||
JF9 | 40.0 mm | 357 x 36.7 mm | -- | 346.8 x 36.7 mm | Hydraulic Hydro-Boost |
1.57 in | 14.00 x 1.44 in | -- | 13.60 x 1.44 in |
