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Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 333 (Hydraulic Brake System) >> Diagnostic Information and Procedures >> Brakes Drag

Brakes Drag

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2011 GMC Yukon XL, 2011 GMC Yukon, 2011 Chevrolet Tahoe, 2011 Chevrolet Suburban, and 2011 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
Brakes Drag

Step Action Yes No
DEFINITION: Brake system does not fully release or has delayed release; vehicle motion may be hindered by brake system without applying brakes.
1 Were you sent here from the Hydraulic Brake Symptom table? Go to Step 2  Go to Diagnostic Starting Point - Vehicle
2 Is the vehicle equipped with an adjustable stop lamp switch and/or an adjustable cruise control release switch? Go to Step 3  Go to Step 4 
3
  1. Inspect the stop lamp switch for proper adjustment to ensure that the brake pedal is fully releasing.
  2. Inspect the cruise control release switch, if equipped, for proper adjustment to ensure that the brake pedal is fully releasing.
Did you find and correct a condition?		 Go to Step 14  Go to Step 4 
4 Is the vehicle equipped with a drum-in-rotor type of park brake system? Go to Step 5  Go to Step 7 
5 Ensure the park brake shoes are not adjusted too tightly, possibly causing drag under certain conditions.
Are the park brake shoes adjusted too tightly?		 Go to Step 6  Go to Step 7 
6
  1. Clean and inspect the park brake shoes for excessive wear and/or damage.
  2. Inspect the drum portion of the rotors for excessive wear, blueing discoloration and heat spots.
  3. If any of these conditions are present, replace the affected components.
  4. Adjust the park brake system.
Did you find and correct a condition?		 Go to Step 14  Go to Step 7 
7 Inspect the park brake system for proper operation. Refer to Park Brake System Diagnosis .
Did you find and correct a condition?		 Go to Step 14  Go to Step 8 
8
  1. Inspect the disc brake system for the following conditions:
    • Binding, incorrectly installed or missing caliper hardware and/or lining hardware-Ensure free movement of linings and of caliper, if equipped with sliding type caliper
    • Lack of lubrication or excessive corrosion on metal to metal contact surfaces
    • Distorted or damaged linings
    • Damaged or excessively worn caliper hardware and/or lining hardware
    • Bent or damaged caliper or mounting component
  2. Adjust, repair or replace components as necessary. Refer to Disc Brake System Diagnosis .
Did you find and correct a condition?		 Go to Step 14  Go to Step 9 
9
  1. Separate the brake booster pushrod from the brake pedal.
  2. Inspect the brake corners to determine if the brake drag condition is still present.
Do the brake corners still exhibit the brake drag condition?		 Go to Step 11  Go to Step 10 
10
  1. Inspect the pushrod for improper positioning and/or damage. Correctly position or replace the pushrod if necessary.
  2. Inspect the brake pedal assembly for damage and replace if necessary.
Did you complete the repair or replacement?		 Go to Step 14  -
11
  1. For vacuum boost systems, disconnect the vacuum check valve from the booster to relieve vacuum reserve.
  2. Separate the master cylinder from the brake booster. Do not disconnect any brake pipes.
  3. Inspect the brake corners to determine if the brake drag condition is still present.
Do the brake corners still exhibit the brake drag condition?		 Go to Step 13  Go to Step 12 
12 Replace the brake booster assembly.
Did you complete the replacement?		 Go to Step 14  -
13
  1. Inspect the hydraulic brake system for the following conditions.
    • Improper operation of caliper pistons
    • Contaminated brake fluid
    • Internally damaged flexible brake hoses; hindering brake release
    • Damaged or improperly operating master cylinder
  2. Adjust, repair or replace components as necessary. Refer to Hydraulic Brake System Diagnosis .
Did you find and correct a condition?		 Go to Step 14  Go to Diagnostic Starting Point - Vehicle
14
  1. Install or connect components that were removed or disconnected during diagnosis.
  2. Road test the vehicle in order to confirm proper operation. Refer to Brake System Vehicle Road Test .
Is the condition still present?		 Go to Step 2  System OK
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