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Chevrolet Silverado / GMC Sierra. Manual - part 1507
16. Compare the brake rotor assembled LRO to the following specification:
Specification - JD9, JH6, JH7 Front and JH6, JH7 Rear: Brake rotor maximum
allowable assembled lateral runout: 0.13 mm (0.005 in)
Specification - JF3, JF7 Front: Brake rotor maximum allowable assembled lateral
runout: 0.05 mm (0.002 in)
Specification - JD9 Rear: Brake rotor maximum allowable assembled lateral runout:
0.25 mm (0.010 in)
17. If the brake rotor assembled LRO measurement exceeds the specification, bring the LRO to
within specifications. Refer to Brake Rotor Assembled Lateral Runout Correction.
18. If the brake rotor assembled LRO measurement is within specification, install the brake
caliper and depress the brake pedal several times to secure the rotor in place before
removing the J 45101-100 and the lug nuts. See Special Tools.
BRAKE PAD INSPECTION
CAUTION: Refer to Brake Dust Caution .
2008 Chevrolet Silverado 1500
2008 BRAKES Disc Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Fig. 7: View Of Brake Pads & Audible Wear Sensors
Courtesy of GENERAL MOTORS CORP.
Inspect the disc brake pads at regular intervals, or whenever the tire and wheel assemblies
are removed from the vehicle.
If replacement is necessary, always replace disc brake pads in axle sets.
Inspect both edges of the disc brake pad friction surfaces (3). The highest rate of wear
normally occurs at the trailing edge of the disc brake pads.
Inspect the thickness of the disc brake pads (3) in order to ensure that they have not worn
prematurely. The disc brake pad wear should be approximately even per axle set.
Both front and rear disc brake pads have integral, audible wear sensors (1). When the disc
brake pad wear reaches the minimum allowable thickness, the wear sensor contacts the disc
2008 Chevrolet Silverado 1500
2008 BRAKES Disc Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
brake rotor (2). The wear indicator will then produce an audible, high-pitched warning
noise during wheel rotation.
Replace the disc brake pads when the friction surface (3) is worn to within 0.76 mm (0.030
in) of the mounting plates.
Remove the brake calipers and inspect the friction surfaces of the inner and outer disc brake
pads to ensure that they are level. Place the disc brake pad friction surfaces together and
measure the gap between the surfaces. If more than 0.13 mm (0.005 in) gap exists midway
between the length of the disc brake pads, replace the disc brake pads.
Verify that any disc brake pad shims that may be required are in place and not damaged or
excessively corroded. Replace any missing or damaged shims in order to preserve proper
disc brake performance.
Replace the disc brake pads if any have separated from the mounting plates.
Inspect the disc brake pads friction surfaces for cracks, fractures, or damage which may
cause noise or otherwise impair disc brake performance.
BRAKE CALIPER INSPECTION
CAUTION: Refer to Brake Dust Caution .
2008 Chevrolet Silverado 1500
2008 BRAKES Disc Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Fig. 8: View Of Brake Caliper Pistons, Boots & Seals
Courtesy of GENERAL MOTORS CORP.
1. Inspect the brake caliper housing for cracks, excess wear, and/or damage. If any of these
conditions are present, the brake caliper requires replacement.
2. Inspect the caliper piston dust boot seals for cracks, tears, cuts, deterioration and/or
improper seating in the caliper body. If any of these conditions are present, the brake caliper
requires overhaul or replacement.
3. Inspect for brake fluid leakage around the caliper piston dust boot seals and on the disc
brake pads. If there is any evidence of brake fluid leakage, the brake caliper requires
overhaul or replacement.
2008 Chevrolet Silverado 1500
2008 BRAKES Disc Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
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