Inspection And Verification

CAUTION: Diagnosis by substitution from a donor vehicle is NOT acceptable. Substitution of control modules does not guarantee confirmation of a fault and may also cause additional faults in the vehicle being checked and/or the donor vehicle.

NOTE: Check and rectify basic faults before beginning diagnostic routines involving pinpoint tests.

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

Visually inspect for obvious signs of mechanical damage.

Visual Inspection

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

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.
If the cause is not visually evident, verify the symptom and refer to the Symptom Chart, alternatively check for Diagnostic Trouble Codes (DTCs) and refer to the DTC Index.

Symptom Chart

Symptom	Possible Causes	Action
Brake noise	Debris Brake pads Brake disc(s)	Remove the debris Install new brake pads as necessary Install new brake discs as necessary
Brake vibration	Suspension components Brake disc(s)	Check the installation of the suspension components Refer to the relevant section of the workshop manual and test the brake disc runout
Excessive brake pedal travel/brake pedal spongy	Brake pads Worn brake pads may make the pedal travel excessive New brake pads may make the pedal spongy Air in the brake system If the pedal "pumps-up", suspect air in the system Brake master cylinder If the pedal sinks to the floor when held under pressure when there are no external leaks, suspect a master cylinder fault Brake fluid leak (see visual inspection)	Install new brake pads as necessary. Road test to bed in the brake pads Check for a cause for air ingress, rectify as necessary Install a new brake master cylinder as necessary Rectify the brake fluid leak as necessary
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 caliper slides Check the brake caliper pistons Check the brake vacuum hose for air leaks Check the brake vacuum pump operation 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 for damaged brake pipes Check the brake pads Check the brake caliper pistons Check the brake caliper slides Check the brake discs
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 electric park brake cable(s) for operation/condition. Check that the cable end connector(s) are correctly installed to the operating lever(s) Check the electric park brake shoes for wear Check the electric park brake shoes for correct adjustment Check the rear brake disc(s)/drum(s) Check the electric park brake actuator for damage and/or excessive noise in normal operation
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 Check the brake pads Refer to the electrical circuit diagrams and test the brake pad wear sensor circuit for short circuit to ground, short circuit to power, open circuit, high resistance Refer to the electrical circuit diagrams and test the brake fluid level sensor circuit for short circuit to ground, short circuit to power, open circuit, high resistance