Subaru 2009 IMPREZA Service Manual page 2614

19.General Diagnostic Table
A: INSPECTION
1. Insufficient braking (1) Fluid leakage from the hydraulic mechanism
(2) Entry of air into the hydraulic mechanism
(3) Wear, deteriorated surface material, water or fluid on
lining
(4) Improper operation of master cylinder, disc caliper,
brake booster or check valve
2. Unstable or uneven (1) Fluid on lining or rotor
braking
(2) Rotor defective
(3) Improper lining contact, deteriorated surface, deterio-
rated or worn lining material
(4) Deformed back plate
(5) Overinflation of tires
(6) Defective wheel alignment
(7) Loose back plate or support installation bolt
(8) Faulty wheel bearing
(9) Defective hydraulic system
(10) Unstable performance of the parking brake
3. Excessive pedal (1) Entry of air into the hydraulic mechanism
stroke
(2) Excessive play in the master cylinder push rod
(3) Fluid leakage from the hydraulic mechanism
(4) Improper lining contact or worn lining
4. Brake dragging or (1) Insufficient pedal play
improper brake
(2) Improper master cylinder return
return
(3) Clogged hydraulic system
(4) Improper return or adjustment of parking brake
(5) Weakened spring tension or breakage of shoe return
spring
(6) Improper disc caliper operation
(7) Faulty wheel bearing
5. Brake noise (1) (1) Hardened or deteriorated brake pad
(creaking sound)
(2) Worn brake pad
(3) Loose back plate or support installation bolt
(4) Loose wheel bearing
(5) Dirty rotor
6. Brake noise (2) (1) Worn brake pad
(hissing sound)
(2) Improperly installed pad
(3) Loose or bent rotor
7. Brake noise (3) Excessively worn pad or support
(click sound)
General Diagnostic Table
Trouble and possible cause
BR-47
Corrective action
Correct or replace. (cup, piston seal, piston
boot, master cylinder piston kit, pipe or
hose)
Bleed air.
Replace, grind or clean.
Correct or replace.
Correct the cause of fluid leakage, and
clean or replace.
Repair or replace the rotor.
Repair by grinding, or replace.
Correct or replace.
Adjust the air pressure.
Adjust alignment.
Tighten to the specified torque.
Replace.
Replace the cylinder, brake pipe or hose.
Check, adjust or replace the rear brake and
cable system.
Bleed air.
Adjust.
Correct or replace. (cup, piston seal, piston
boot, master cylinder piston kit, pipe or
hose)
Correct or replace.
Adjust play.
Clean or replace the cylinder.
Replace.
Repair or adjust.
Replace the spring.
Correct or replace.
Replace.
Replace the pad.
Replace the pad.
Tighten to the specified torque.
Tighten to the specified torque.
Clean the rotor, or clean and replace brake
assembly.
Replace the pad.
Correct or replace the pad.
Retighten or replace.
Replace the pad or the support.
BRAKE