Symptom Related Diagnostic Procedures

NOTE: Brake friction material inherently generates noise and heat to dissipate energy. As a result, occasional squeal is possible, and it is aggravated by severe environmental conditions such as cold, heat, wet, snow, salt, mud and other conditions.


BRAKES PULL OR DRIFT

Possible Cause
- Worn/damaged brake shoe and lining
- Abnormal Wear or distortion of front disc brake rotor
- Rear disc brake caliper piston and adjuster malfunction
- Improper rear brake adjustment
- Improper wheel alignment adjustment
- Loose or damaged brake rotor shield mounting bolt
- Improper wheel bearing preload
- unequal tire inflation pressure
- Brake linings contaminated or glazed
- calipers stuck or seized

Action - Go to pinpoint test A.
A - Brakes Pull or Drift

BRAKE WARNING INDICATOR ALWAYS "ON"

Possible Cause
- Low fluid level.
- Leaking brake master cylinder primary piston cup.
- Parking brake control not fully released.
- Shorted indicator circuit.

Action - Go to pinpoint test B.
B - Brake Warning Indicator Always ON

VIBRATION WHEN BRAKES ARE APPLIED

Possible Cause
- Grease or fluid on brake shoe and lining.
- Glazed brake shoe and lining.
- Worn brake hoe and lining.
- Loose caliper mounting bolt.
- Insufficient grease on sliding parts.
- Foreign material or scratches on rear disc brake rotor contact surface.
- Damaged drum contact surface.
- Loose or missing wheel hub bolt nuts.
- Rotor thickness variation too high.

Action - Go to pinpoint test C.
C - Vibration When Brakes Are Applied

PEDAL GOES DOWN FAST

Possible Cause
- Leak in hydraulic system.
- Air in System
- Worn brake master cylinder piston cups or scored cylinder bore.
- Disc brake 'knock back' excessive. (Pads push caliper pistor back into caliper. caused by excessive disc brake rotor lateral runout or loose wheel bearings.)

Action - Go to pinpoint test D.
D - Brake Pedal Goes Down Fast

PEDAL EASES DOWN SLOWLY

Possible Cause
- Air in system.
- Malfunctioning brake master cylinder.

Action - Go to pinpoint test E.
E - Pedal Goes Down Slowly

PEDAL IS LOW OR FEELS SPONGY

Possible Cause
- Brake shoe and lining.
- Hydraulic system.

Action - Go to pinpoint test F.
F - Pedal Is Low or Feels Spongy

BRAKE LOCKUP DURING LIGHT BRAKE PEDAL FORCE

Possible Cause
- Incorrect tire pressure.
- Tires worn. REPLACE worn tires.
- Glazed or worn brake shoe and linings.
- Dragging brake.

Action - Go to pinpoint test G.
G - Brakes Lockup When Applied

EXCESSIVE/ERRATIC PEDAL TRAVEL

Possible Cause
- Worn brake shoe and lining.
- Disc brake rotor runout.
- Air in system.

Action - Go to pinpoint test H.
H - Excessive and/or Erratic Pedal Travel

BRAKES DRAG

Possible Cause
- Power brake booster.
- Brake pressure control valve.
- Disc brake caliper seized or stuck.

Action - Go to pinpoint test J.
J - Brakes Drag

EXCESSIVE BRAKE PEDAL EFFORT

Possible Cause
- Power brake booster inoperative.
- Worn or contaminated brake shoes and linings.

Action - Go to pinpoint test K.
K - Excessive Brake Pedal Effort

BRAKE NOISE

Possible Cause
- Brake shoe and lining.
- Power brake booster.

Action - Go to pinpoint test L.
L - Brake Noise

SLOW OR INCOMPLETE BRAKE PEDAL RETURN

Possible Cause
- Power brake booster.
- Brake master cylinder.

Action - Go to pinpoint test M.
M - Slow or Incomplete Brake Pedal Return