GM Service Manual Online
For 1990-2009 cars only

Series

System

Front Brakes

Rear Brakes

Brake Assist/Max. Pedal Travel

1500 (6100/7100 GVW) 2500 (7300 GVW)

JB6

Disc 11.57 x 1.25

Drum 11.15 x 2.75

Vacuum, 60-65 mm (2.3-2.6 in.)

2500 (8600 GVW)

JD7

Disc 12.50 x 1.26

Drum 13.00 x 2.50

(Diesel 13.00 x 3.50

Hydraulic, 85-90 mm (3.3-3.6 in.)

3500 Single Wheel

JB8

Disc 12.50 x 1.26

Drum 13.00 x 3.50

Hydraulic, 85-90 mm (3.3-3.6 in.)

3500 Dual Wheel

JB8

Disc 12.50 x 1.50

Drum 13.00 x 3.50

Hydraulic, (3.3-3.6 in.)