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Chevrolet Silverado / GMC Sierra. Manual - part 2370
12
Missing balance weights
Braking Surface Wear Conditions
Deep or excessive scoring
beyond maximum acceptable
level
Radial runout beyond maximum
acceptable level
2. Make a determination for each brake drum
if the drum requires replacement based
upon the results of the inspection.
If a brake drum exhibits any of the
following conditions, it requires
replacement.
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 REPLACEMENT?
IMPORTANT:
Make the following determination AND
ANSWER the question INDIVIDUALLY for
EACH drum.
Go to Step 13
Go to Step 14
13
Replace the brake drum. Refer to Brake Drum
Replacement .
Did you complete the replacement?
Go to Step 14
-
14
Inspect the brake shoes for proper adjustment.
Refer to Drum Brake Adjustment .
Are the brake shoes adjusted properly?
Go to Step 18
Go to Step 15
15
Inspect the components of the brake drum
adjustment hardware system for free movement
and correct operation. Refer to Drum Brake
Adjusting Hardware Inspection .
2008 Chevrolet Silverado 1500
2008 BRAKES Hydraulic Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
HYDRAULIC BRAKE SYSTEM DIAGNOSIS
Do the drum brake adjusting hardware
components operate freely and correctly?
Go to Step 17
Go to Step 16
16
Replace the drum brake adjusting hardware
components as necessary. Refer to Drum Brake
Adjusting Hardware Replacement .
Is the replacement complete?
Go to Step 17
-
17
Adjust the drum brake shoes. Refer to Drum
Brake Adjustment .
Were you able to complete the adjustment?
Go to Step 20
Return to
Symptom Table
18
Inspect the drum brake backing plate for the
following:
Excessive wear or rust
Damage and/or evidence of contact with
the brake drum
Does the drum brake backing plate exhibit any
of these conditions?
Go to Step 19
Go to Step 20
19
Repair or replace the drum brake backing plate
as necessary. Refer to Rear Brake Backing
Plate Replacement .
Did you complete the repair or replacement?
Go to Step 20
-
20
Install or connect components that were removed
or disconnected during diagnosis.
Did you complete the operation?
Drum Brake
System OK
Return to
Symptom Table
-
Step
Action
Yes
No
DEFINITION: This diagnostic table is designed to diagnose ONLY the components of the
HYDRAULIC brake system in order to determine if the HYDRAULIC 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
Diagnostic
Starting Point -
Hydraulic
2008 Chevrolet Silverado 1500
2008 BRAKES Hydraulic Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Go to Step 2 Brakes
2
Inspect and adjust the brake fluid level in the
brake master cylinder. Refer to Master
Cylinder Reservoir Filling.
Was the brake fluid level low?
Go to Step 3
Go to Step 4
3
1. Inspect the brake fluid for the following
conditions, indicating brake fluid
contamination:
Fluid separation, indicating two types
of fluid are present
Swirled appearance - oil-based
substance
Layered appearance - silicone-
based substance
Fluid discoloration
Cloudy appearance - moisture
Dark appearance/suspended
particles in fluid - dirt, rust,
corrosion, brake dust
2. Inspect the master cylinder reservoir cap
diaphragm and the reservoir-to-master
cylinder grommets for swelling, indicating
fluid contamination.
Do any of the above conditions exist?
Go to Step 5
Go to Step 6
4
1. Inspect the brake fluid for the following
conditions, indicating brake fluid
contamination:
Fluid separation, indicating two types
of fluid are present
Swirled appearance - oil-based
substance
Layered appearance - silicone-
based substance
Fluid discoloration
Cloudy appearance - moisture
2008 Chevrolet Silverado 1500
2008 BRAKES Hydraulic Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Dark appearance/suspended
particles in fluid - dirt, rust,
corrosion, brake dust
2. Inspect the master cylinder reservoir cap
diaphragm and the reservoir-to-master
cylinder grommets for swelling, indicating
fluid contamination.
Do any of the above conditions exist?
Go to Step 5
Go to Step 12
1. Flush the hydraulic brake system. Refer to
Hydraulic Brake System Flushing.
2. If the brake fluid WAS contaminated with
an oil-based or a silicone-based fluid,
indicated by fluid separation and/or a
swollen master cylinder reservoir cap
diaphragm and/or swollen reservoir-to-
master cylinder grommets, perform the
following steps. Refer to the procedures
indicated.
1. Remove ALL of the following
components listed. Each component
contains internal rubber seals/linings
which have been contaminated.
2. Clean out the hydraulic brake pipes
using denatured alcohol, or equivalent.
3. Dry the brake pipes using non-
lubricated, filtered air.
4. Repair or replace ALL of the
following components listed. Each
component contains internal rubber
seals/linings which have been
contaminated.
Master Cylinder Replacement
(JD9, JF3, JF7)Master
Cylinder Replacement (JH6,
JH7)
Brake master cylinder reservoir:
2008 Chevrolet Silverado 1500
2008 BRAKES Hydraulic Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Content .. 2368 2369 2370 2371 ..