Series  | System  | Rear Brakes  | Brake Assist  | 
|---|---|---|---|
1500 (6100/7100 GVW) 2500 (7300 GVW)  | JB6  | 11.15 x 2.75  | Vacuum  | 
2500 (8600 GVW)  | JD7  | Gas 13.00 x 2.50 Diesel 13.00 x 3.50  | Hydraulic  | 
3500 Single Wheel  | JB8  | 13.00 x 3.50  | Hydraulic  | 
3500 Dual Wheel  | JB8  | 13.00 x 3.50  | Hydraulic  |