:  Dec 21, 2007



Principle of Operation

The brake system is a fairly straightforward design requiring no specialized techniques for diagnosis.

For information on the description and operation of the system, refer to the relevant section of the workshop manual.

Inspection and Verification

. Verify the customer concern.
  If a road test is necessary make sure the vehicle is safe to do so.
If a road test is necessary make sure the vehicle is safe to do so.

. Visually inspect for obvious mechanical faults.

Mechanical
  • Brake pad(s) condition and installation
  • Brake caliper(s) condition and installation
  • Brake disc(s) condition and installation
  • Parking brake disc(s)/parking brake drum(s) condition and installation
  • Parking brake shoes condition and installation
  • Parking brake cable(s) condition and installation
  • Brake booster condition and installation
  • Brake booster vacuum hose condition and installation
  • Brake master cylinder condition and installation
  • Hydraulic control unit (HCU)
  • Brake fluid leaks
  • Brake warning indicator

. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.

. Use the approved diagnostic system or a scan tool to retrieve any diagnostic trouble codes (DTCs) before moving onto the symptom chart.
  For a list of diagnostic trouble codes (DTCs) referring to the anti-lock brake system, refer to section 206-09 - Traction Control in the workshop manual.
For a list of diagnostic trouble codes (DTCs) referring to the anti-lock brake system, refer to section 206-09 - Traction Control in the workshop manual.
  Make sure that all DTCs are cleared following rectification
Make sure that all DTCs are cleared following rectification

Symptom Possible causes Action
Brake noise
  • Debris
  • Brake pads
  • Brake disc(s)
Refer to the relevant section of the workshop manual.
Brake vibration
  • Suspension components
  • Brake disc(s)
Refer to the relevant section of the workshop manual.
Excessive brake pedal travel/brake pedal spongy
  • Brake pads
  • Air in the brake system
  • Brake master cylinder
  • Brake fluid leak (see visual inspection)
Worn pads may make the pedal travel excessive, new pads may make the pedal spongy. Check after bedding in the pads. Check the pedal travel. If the pedal "pumps-up", suspect air in the system. Check for a cause for air ingress, rectify as necessary. If the pedal sinks to the floor when held under pressure when there are no external leaks, suspect a master cylinder fault. Refer to the relevant section of the workshop manual.
Excessive brake pedal effort/brake pedal hard
  • Brake pipe(s)
  • Brake caliper slide(s)
  • Brake caliper piston(s)
  • Brake vacuum pipe
  • Brake vacuum pump
  • Brake booster
Check for damaged brake pipes. Check the brake calipers. Check the brake vacuum pipe for air leaks, rectify as necessary. Check the brake vacuum pump operation. Refer to the relevant section of the workshop manual. Check the brake booster.
Low foot brake efficiency/brakes pulling/sticking/binding
  • Brake pipe(s)
  • Pads
  • Brake caliper piston(s)
  • Brake caliper slide(s)
  • Brake disc(s)
Check the vehicle for damaged brake pipes. Inspect the brake pads. Check the brake calipers. Check the brake discs. Refer to the relevant section of the workshop manual.
Parking brake will not engage or release
  • Parking brake cables
  • Parking brake shoes
  • Parking brake adjusters
  • Rear brake disc(s)/parking brake drum(s)
  • Parking brake actuator malfunction
Check the parking brake cable(s) for operation/condition. Check that the cable end connector(s) are correctly installed to the operating lever(s). Inspect the parking brake shoes for wear. Check the parking brake shoes for correct adjustment. Check the rear brake disc(s)/parking brake drum(s). Check the parking brake actuator for damage and/or excessive noise in normal operation. Refer to the relevant section of the workshop manual.
Low parking brake efficiency/parking brake sticking/binding
Brake warning indicator staying illuminated
  • Brake reservoir fluid level
  • Brake pads
  • Brake pad wear sensor leads
  • Brake fluid level sensor
Check the brake fluid level, top up if required. Inspect the brake pads. Check the brake pad sensor circuit. Refer to the electrical guides. Check the function of the brake fluid level sensor. Refer to the relevant section of the workshop manual.