Chevrolet Silverado / GMC Sierra. Service manual — part 2369

DRUM BRAKE SYSTEM DIAGNOSIS

Test Description

The number below refers to the step number on the diagnostic table:

18: Drum brake backing plates that come in contact with brake drums may cause brake
system noise.

Step

Action

Yes

No

DEFINITION: This diagnostic table is designed to diagnose ONLY the components of the
DRUM brake system in order to determine if the DRUM brake system is operating
properly. You will be directed by the appropriate Symptom table to go to other brake
system diagnostic tables as appropriate.

1

Were you sent here from a Brake Symptom
table?

Go to Step 2

Go to

2

1. Remove the brake drums. Refer to Brake

Drum Replacement .

2. Inspect the drum brake shoes for the

following conditions:

Lining thickness below specifications

Uneven and/or abnormal wear - edge-
to-edge and/or side-to-side

Contamination from an external
substance

Looseness, damage, glazing, or
incorrect lining material

Did you find any conditions to indicate a
concern with any of the drum brake shoes?

Go to Step 3

Go to Step 7

3

Are any of the brake shoes contaminated?

Go to Step 4

Go to Step 5

4

1. Inspect the wheel cylinders for evidence of

an external brake fluid leak.

2. Replace any wheel cylinder that is found to

be leaking brake fluid. Refer to Wheel
Cylinder Replacement .

Did you complete the inspection and

-

2008 Chevrolet Silverado 1500

2008 BRAKES Hydraulic Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

replacement?

Go to Step 6

5

1. Inspect the drum brake hardware for any

components which are worn, damaged,
discolored due to stress, broken or missing.
Refer to Drum Brake Adjusting
Hardware Inspection .

2. Replace components as required. Refer to

Brake Shoe Replacement .

3. Replace the drum brake shoes. Refer to

Brake Shoe Replacement .

Did you complete the inspection and
replacement?

Go to Step 8

-

6

1. Clean the remaining drum brake system

components to remove any traces of the
contaminant.

2. Inspect the drum brake hardware for any

components which are worn, damaged,
discolored due to stress, broken or missing.
Refer to Drum Brake Adjusting
Hardware Inspection .

3. Replace the drum brake hardware

components as required. Refer to Brake
Shoe Replacement .

4. Replace the contaminated brake shoes.

Refer to Brake Shoe Replacement .

Did you complete the cleaning, inspection and
replacement?

Go to Step 8

-

7

1. Inspect the drum brake hardware for any

components which are worn, damaged,
discolored due to stress, broken or missing.
Refer to Drum Brake Adjusting
Hardware Inspection .

2. Replace components as required. Refer to

Brake Shoe Replacement .

-

2008 Chevrolet Silverado 1500

2008 BRAKES Hydraulic Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

Did you complete the inspection and, if
necessary, the replacement?

Go to Step 8

8

1. Check the diameter of each of the brake

drums.

2. Make a determination for each brake drum

if the drum can be REFINISHED and
REMAIN ABOVE the minimum
requirements.

Refer to Brake Drum Diameter
Measurement .Does the brake drum meet the
minimum requirements for REFINISHING?

IMPORTANT:

Make the following determination AND
ANSWER the question INDIVIDUALLY for
EACH drum.

Go to Step 9

Go to Step 11

9

1. Inspect each of the brake drums for the

following surface and wear conditions:

Refer to Brake Drum Surface and Wear
Inspection .

Braking Surface Conditions

Heavy rust and/or pitting

Cracks and/or heat spots

Excessive blueing discoloration

Missing balance weights

Braking Surface Wear Conditions

Deep or excessive scoring
beyond maximum acceptable
level

Radial runout beyond maximum
acceptable level

IMPORTANT:

Make the following determination AND

2008 Chevrolet Silverado 1500

2008 BRAKES Hydraulic Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

2. Make a determination for each brake drum

if the drum requires refinishing based upon
the results of the inspection.

If the brake drum exhibits any of the
following conditions, it requires
refinishing.

Drum exhibits one or more of the
Braking Surface Conditions listed
previously

Drum is beyond the acceptable level
in one or more of the Braking Surface
Wear Conditions listed previously

Does the brake drum require REFINISHING?

ANSWER the question INDIVIDUALLY for
EACH drum.

Go to Step 10

Go to Step 14

10

1. Refinish the brake drum. Refer to Brake

Drum Refinishing .

2. Inspect the brake drum diameter. Refer to

Brake Drum Diameter Measurement .

Were you able to REFINISH the brake drum
within the minimum requirements?

Go to Step 14

Go to Step 13

11

Is the brake drum at or below the DISCARD
requirements?

Go to Step 13

Go to Step 12

1. Inspect each of the brake drums for the

following surface and wear conditions:

Refer to Brake Drum Surface and Wear
Inspection .

Braking Surface Conditions

Heavy rust and/or pitting

Cracks and/or heat spots

Excessive blueing discoloration

2008 Chevrolet Silverado 1500

2008 BRAKES Hydraulic Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado