GM Service Manual Online
For 1990-2009 cars only

Application

Specification

Metric

English

Front Brakes JC3/JC4

  • Rotor Discard Thickness

27.50 mm

1.083 in

  • Rotor Minimum Allowable Thickness After Refinish

28.0 mm

1.102 in

  • Rotor Thickness (new)

29.0 mm

1.142 in

  • Rotor Maximum Allowable Lateral Runout

0.13 mm

0.005 in

  • Rotor Maximum Allowable Scoring

1.50 mm

0.059 in

  • Rotor Maximum Allowable Thickness Variation

0.025 mm

0.001 in

Front Brakes JH2

  • Rotor Discard Thickness

27.50 mm

1.083 in

  • Rotor Minimum Allowable Thickness After Refinish

28.0 mm

1.102 in

  • Rotor Thickness (new)

29.0 mm

1.142 in

  • Rotor Maximum Allowable Lateral Runout

0.13 mm

0.005 in

  • Rotor Maximum Allowable Scoring

1.50 mm

0.059 in

  • Rotor Maximum Allowable Thickness Variation

0.025 mm

0.001 in

Front Brakes JH6

  • Rotor Discard Thickness

36.50 mm

1.437 in

  • Rotor Minimum Allowable Thickness After Refinish

37.0 mm

1.457 in

  • Rotor Thickness (new)

38.0 mm

1.496 in

  • Rotor Maximum Allowable Lateral Runout

0.13 mm

0.005 in

  • Rotor Maximum Allowable Scoring

1.50 mm

0.059 in

  • Rotor Maximum Allowable Thickness Variation

0.025 mm

0.001 in

Rear Brakes JC4

  • Rotor Discard Thickness

28.5 mm

1.122 in

  • Rotor Minimum Allowable Thickness After Refinish

29.0 mm

1.142 in

  • Rotor Thickness (new)

30.0 mm

1.181  in

  • Rotor Maximum Allowable Lateral Runout

0.13 mm

0.005 in

  • Rotor Maximum Allowable Scoring

1.50 mm

0.059 in

  • Rotor Maximum Allowable Thickness Variation

0.025 mm

0.001  in

Rear Brakes JH2

  • Rotor Discard Thickness

28.5 mm

1.122 in

  • Rotor Minimum Allowable Thickness After Refinish

29.0 mm

1.142 in

  • Rotor Thickness (new)

30.0 mm

1.181  in

  • Rotor Maximum Allowable Lateral Runout

0.13 mm

0.005 in

  • Rotor Maximum Allowable Scoring

1.50 mm

0.059 in

  • Rotor Maximum Allowable Thickness Variation

0.025 mm

0.001 in

Rear Brakes JH6

  • Rotor Discard Thickness

27.5 mm

1.083 in

  • Rotor Minimum Allowable Thickness After Refinish

28.0 mm

1.102 in

  • Rotor Thickness (new)

29.0 mm

1.142  in

  • Rotor Maximum Allowable Lateral Runout

0.13 mm

0.005 in

  • Rotor Maximum Allowable Scoring

1.50 mm

0.059 in

  • Rotor Maximum Allowable Thickness Variation

0.025 mm

0.001 in

* All brake rotors have a discard dimension cast into them. Replace any rotor that does not meet this specification. After refinishing the rotor, replace any rotor that does not meet the minimum thickness specifications.