BRAKE SYSTEM INSPECTION/VERIFICATION

id041000800200

Inspection/Verification

Warning
• Brake fluid contains polyglycol ethers and polyglycols. Avoid contact with eyes. Wash hands thoroughly after handling. If brake fluid contacts eyes, flush eyes with running water for 15 minutes. Get medical attention if irritation persists. If taken internally, drink water and induce vomiting. Get medical attention immediately. Failure to follow these instructions may cause personal injury.
Caution
• Brake fluid will damage painted surfaces. Be careful not to spill any on painted surfaces. If brake fluid is spilled, wipe it off immediately.
Note
• Always check the fluid level in the brake master cylinder before carrying out the test procedures. If the fluid level is not at the MAX line, add specified brake fluid.
• Prior to carrying out any diagnosis, verify that the brake system warning light is functional. Apply the parking brake. If the brake system warning light does not illuminate, refer to the instrument cluster inspection. (See INSTRUMENT CLUSTER INSPECTION [L3].) (See INSTRUMENT CLUSTER INSPECTION [EXCEPT L3].)

1. The first indicator of brake system concerns is a change in the feeling through the brake pedal. The brake system warning light and the brake fluid level are also effective to find any malfunction of the system. Verify the symptom, and conduct corresponding diagnosis.

Symptom Troubleshooting Chart

Troubleshooting Item

Possible Cause

No.

Brakes pull or drift
• Improper tire pressure
• Incorrect wheel alignment
• Foreign material on brake shoes and linings
• Worn or damaged brake shoes and linings
• Binding or sticking brake components
• Abnormal wear or distortion of disc plates or brake drums
• Loose or damaged suspension components
1
The brake system warning light is always illuminated
• Parking brake not fully released
• Low brake fluid level
• Brake system warning light circuit malfunction
• Brake master cylinder inoperative
2
Vibration when brakes are applied
• Disc plates have excessive lateral runout
• Brake drums out-of-round
3
Brake pedal goes down fast
• Low brake fluid level
• Air in brake system
• Brake master cylinder inoperative
4
Brake pedal eases down slowly
• Air in brake system
• Brake master cylinder inoperative
5
Brake pedal is low or feels spongy
• Low brake fluid level
• Air in brake system
• Brake master cylinder inoperative
• Worn or damaged brake shoes and linings
• Brake switch
6
Brake lockup during light brake pedal force
• Binding or sticking wheel cylinder or disc brake caliper
• Worn or damaged brake shoes and linings
• Loose rear brake backing plate
• Binding or sticking parking brake components
• ABS system malfunction
7
Excessive/Erratic brake pedal travel
• Leak in hydraulic system
• Air in brake system
• Binding or sticking disc brake caliper or rear wheel cylinder
• Brake master cylinder inoperative
• Brake switch
8
Brakes drag
• Binding or sticking parking brake components
• Binding or sticking disc brake caliper or rear wheel cylinder
• Brake master cylinder inoperative
• Brake switch
9
Brake noise
• Worn or damaged brake shoes and linings
• Glazed or damaged disc plates or brake drums
• Damaged brake backing plates
• Foreign material on brake shoes and linings
• Damaged or missing brake shoe and return springs and/or guide plates
• Dry or rough brake shoe and lining contact points on backing plates
• Loose mounting support installation bolts
10
Excessive brake pedal effort
• Lack of vacuum to the power brake unit
• Vacuum check valve inoperative
• Restricted power brake booster hose
• Power brake unit inoperative
• Brake pedal binding
11
Slow or incomplete brake pedal return
• Brake pedal binding
• Power brake unit binding
• Brake master cylinder inoperative
• Damaged or missing brake drum retracting springs
• Damaged or missing brake pedal return spring
12

No.1 Brakes Pull or Drift

Diagnostic procedure

STEP

INSPECTION

ACTION

1
Inspect the tire pressure.
Is the tire pressure correct?
Yes
Go to the next step.
No
Adjust tire air pressure, then go to the next step.
2
Inspect the wheel alignment.
Is the wheel alignment correct?
Yes
Go to the next step.
No
Adjust the wheel alignment, then go to the next step.
3
Inspect for wear, damage, and foreign objects on brake shoes.
Are the brake shoes normal?
Yes
Go to the next step.
No
Clean or replace brake shoes as necessary, then go to the next step.
4
Inspect for binding or sticking on brake components.
Are the brake components normal?
Yes
Go to the next step.
No
Repair or replace the brake components, then go to the next step.
5
Inspect for abnormal wear or distortion of disc plates or brake drums.
Are the disc plates or brake drums normal?
Yes
Go to the next step.
No
Repair or replace the disc plates or brake drums, then go to the next step.
6
Inspect for any loose or damaged suspension components.
Are the suspension components normal?
Yes
Malfunction diagnosis completed.
No
Repair or replace the suspension components.

No.2 The Brake System Warning Light Is Always Illuminated

Diagnostic procedure

STEP

INSPECTION

ACTION

1
Verify that the parking brake lever is released completely.
Is the parking brake lever released?
Yes
Go to the next step.
No
Release the parking brake lever and go to the next step.
2
Verify that the brake fluid is sufficient.
Is the brake fluid level correct?
Yes
Go to the next step.
No
Inspect the brake system for leaks. Repair or replace as necessary and refill the brake fluid, then go to the next step.
3
Inspect the brake system warning light circuit for malfunction.
Is the circuit normal?
Yes
Go to the next step.
No
Repair or replace the circuit, then go to the next step.
4
Verify that the brake master cylinder functions correctly.
Is the master cylinder normal?
Yes
Malfunction diagnosis completed.
No
Repair or replace the master cylinder.

No.3 Vibration When Brakes Are Applied

Note
• Brake pedal pulsations could be a normal condition.

Diagnostic procedure

STEP

INSPECTION

ACTION

1
Apply brakes and reduce the vehicle speed to 56-80 km/h {35-49 mph}.
Is vibration present when brakes are applied?
Yes
Repair or replace the disc plates or brake drums.
No
This is considered as a concern due to NVH. Identify NVH cause, and repair or replace.

No.4 Brake Pedal Goes Down Fast

Diagnostic procedure

STEP

INSPECTION

ACTION

1
Verify that the brake fluid is sufficient.
Is the brake fluid level correct?
Yes
Go to the next step.
No
Inspect the brake system for leaks. Repair or replace as necessary and refill the brake fluid, then go to the next step.
2
Inspect for air in the brake system.
Is the brake system normal?
Yes
Go to the next step.
No
Bleed the air from the brake system.
Go to the next step.
3
Verify that the master cylinder functions normally.
Is the master cylinder normal?
Yes
Malfunction diagnosis completed.
No
Repair or replace the master cylinder.

No.5 Brake Pedal Eases Down Slowly

Diagnostic procedure

STEP

INSPECTION

ACTION

1
Inspect for air in the brake system.
Is the brake system normal?
Yes
Go to the next step.
No
Bleed the air from the brake system.
Go to the next step.
2
Verify that the master cylinder functions normally.
Is the master cylinder normal?
Yes
Malfunction diagnosis completed.
No
Repair or replace the master cylinder.

No.6 Brake Pedal Is Low Or Feels Spongy

Diagnostic procedure

STEP

INSPECTION

ACTION

1
Verify that the brake fluid is sufficient.
Is the brake fluid level correct?
Yes
Go to the next step.
No
Verify the brake system leaks. Repair or replace as necessary and refill the brake fluid, then go to the next step.
2
Inspect for air in the brake system.
Is the brake system normal?
Yes
Go to the next step.
No
Bleed the air from the brake system.
Go to the next step.
3
Verify that the master cylinder functions normally.
Is the master cylinder normal?
Yes
Go to the next step.
No
Repair or replace the master cylinder.
4
Inspect for wear and damage on brake shoes.
Are the brake shoes normal?
Yes
Go to the next step.
No
Replace brake shoes as necessary, then go to the next step.
5
Inspect the brake switch installation position.
Is the brake switch installation position normal?
Yes
Malfunction diagnosis completed.
No
Adjust the brake switch installation position.

No.7 Brake Lockup During Light Brake Pedal Force

Diagnostic procedure

STEP

INSPECTION

ACTION

1
Reduce the vehicle speed to 56-80 km/h, applying light brake.
Do the brakes lockup?
Yes
Go to the next step.
No
Malfunction diagnosis completed.
2
Inspect for binding or sticking caliper piston, caliper slide pin, wheel cylinder or rear brake components.
Are the components free of binding or sticking?
Yes
Go to the next step.
No
Repair or replace the components.
3
Inspect for damage, binding, or poor adjustment of parking brake components.
Are the parking brake components normal?
Yes
Go to the next step.
No
Repair or replace the components.
4
Inspect for excessive wear, cracks, or separation on the brake shoes.
Are the brake shoes normal?
Yes
Go to the next step.
No
Repair or replace the brake shoes, then go to the next step.
5
Inspect for any loose or damaged front and rear brakes.
Is the installation normal?
Yes
Inspect the ABS system.
No
Repair or replace, as necessary.

No.8 Excessive/Erratic Brake Pedal Travel

Diagnostic procedure

STEP

INSPECTION

ACTION

1
Inspect the brake system for leaks.
Is there any leakage in the brake system?
Yes
Repair or replace the components.
No
Go to the next step.
2
Inspect for air in the brake system.
Is the brake system normal?
Yes
Go to the next step.
No
Bleed the air from the brake system.
Go to the next step.
3
Inspect for binding or sticking wheel cylinder or caliper.
Are the wheel cylinder and caliper normal?
Yes
Go to the next step.
No
Repair or replace the wheel cylinder or the caliper.
4
Verify that the master cylinder functions normally.
Is the master cylinder normal?
Yes
Go to the next step.
No
Repair or replace the master cylinder.
5
Inspect the brake switch installation position.
Is the brake switch installation position normal?
Yes
Malfunction diagnosis completed.
No
Adjust the brake switch installation position.

No.9 Brake Drag

Diagnostic procedure

STEP

INSPECTION

ACTION

1
Inspect for damage, binding or poor adjustment on parking brake components.
Are the parking brake components normal?
Yes
Go to the next step.
No
Repair or replace the components.
2
Inspect for binding or sticking wheel cylinder or caliper.
Are the wheel cylinder and caliper normal?
Yes
Go to the next step.
No
Repair or replace the wheel cylinder or the caliper.
3
Verify that the master cylinder functions normally.
Is the master cylinder normal?
Yes
Go to the next step.
No
Repair or replace the master cylinder.
4
Inspect the brake switch installation position.
Is the brake switch installation position normal?
Yes
Malfunction diagnosis completed.
No
Adjust the brake switch installation position.

No.10 Brake Noise

Diagnostic procedure

STEP

INSPECTION

ACTION

1
Inspect for worn brake shoes and disc pads.
Are the brake shoes and disc pads normal?
Yes
Go to the next step.
No
Replace the brake shoes or disc pads.
2
Inspect for worn or damaged disc plates and brake drums.
Are disc plates and brake drums normal?
Yes
Go to the next step.
No
Replace the disc plates or brake drums.
3
Inspect for damaged backing plates.
Are the backing plates normal?
Yes
Go to the next step.
No
Repair or replace the backing plates.
4
Inspect for foreign objects on brake shoes.
Are the brake shoes normal?
Yes
Go to the next step.
No
Clean or replace the brake shoes.
5
Inspect for damaged brake shoes, return springs or guide plates.
Are the brake shoes, return springs or guide plates normal?
Yes
Go to the next step.
No
Replace the brake shoes, return springs or guide plates.
6
Inspect for dry or rough brake shoe and lining contact points on backing plates.
Are the contact points normal?
Yes
Go to the next step.
No
Repair and lubricate the contact points.
7
Inspect for loose mounting support installation bolts.
Is the mounting support installation normal?
Yes
Malfunction diagnosis completed.
No
Repair the mounting support installation.

No.11 Excessive Brake Pedal Effort

Diagnostic procedure

STEP

INSPECTION

ACTION

1
Operate the brake pedal.
Is excessive brake pedal effort required?
Yes
Go to the next step.
No
Malfunction diagnosis completed.
2
Remove the brake pedal snap pin and clevis pin, and move the power brake unit fork aside.
Operate the brake pedal.
Is excessive brake pedal effort required?
Yes
Repair or replace the brake pedal.
No
Install the power brake unit fork to the brake pedal and inspect the power brake unit.

No.12 Slow or Incomplete Brake Pedal Return

Diagnostic procedure

STEP

INSPECTION

ACTION

1
Operate the brake pedal.
Does the brake pedal return slowly or incompletely?
Yes
Go to the next step.
No
Malfunction diagnosis completed.
2
Remove the brake pedal snap pin and clevis pin, and move the power brake unit fork aside.
Operate the brake pedal.
Does the brake pedal return completely?
Yes
Install the power brake unit fork to the brake pedal, then go to the next step.
No
Repair or replace the brake pedal.
3
Inspect the power brake unit.
Is the power brake unit normal?
Yes
Replace the master cylinder
No
Replace the power brake unit.