GM Service Manual Online
For 1990-2009 cars only
Table 1: Brake Systems Specifications

Brake Systems Specifications

Application

RPO Code

Front Disc Brakes (diameter x thickness)

Rear Drum Brakes (diameter x thickness)

Brake Assist System

M-Van (RWD)

JM4

11.86" x 1.04"

9.5" x 2"

Hydraulic

L-Van (F4WD)

JM4

11.57" x 1.25"

9.5" x 2"

Hydraulic

Application

Specification

Metric

English

M-Van (RWD)

  • Original

26.42 mm

1.04"

  • Thinnest (Refinishing)

24.89 mm

0.980"

  • Replacement (Discard)

24.51 mm

0.965"

L-Van (F4WD)

  • Original

31.75 mm

1.25"

  • Thinnest (Refinishing)

31.25 mm

1.23"

  • Replacement (Discard)

30.86 mm

1.215"