Subaru Impreza 2003 Service Manual page 2610

BRAKE
21.General Diagnostics
A: INSPECTION
1. Insufficient braking (1) Fluid leakage from the hydraulic mechanism
(2) Entry of air into the hydraulic mechanism
(3) Excessively wide shoe clearance
(4) Wear, deteriorated surface material, adhering
water or fluid on the lining
(5) Improper operation of master cylinder, disc cal-
iper, brake booster or check valve
2. Unstable or uneven (1) Fluid on the lining, drum or rotor
braking
(2) Drum or rotor eccentricity
(3) Worn brake drum, or damage to the drum
caused by sand
(4) Improper lining contact, deteriorated surface
material, improper inferior material, or wear
(5) Deformed back plate
(6) Improper tire inflation
(7) Disordered wheel alignment
(8) Loosened back plate or the support installing
bolts
(9) Loosened wheel bearing
(10) Trouble in the hydraulic system
(11) Uneven effect 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) Improperly adjusted shoe clearance
(5) Improper lining contact or worn lining
4. Brake dragging or (1) Insufficient pedal play
improper brake return
(2) Improper master cylinder return
(3) Clogged hydraulic system
(4) Improper return or adjustment of parking brake Correct or adjust.
(5) Weakened spring tension or breakage of shoe
return spring
(6) Excessively narrow shoe clearance
(7) Improper disc caliper operation
(8) Wheel bearing faulty
5. Brake noise (1) (1) Hardened or deteriorated lining
(creak sound)
(2) Worn lining
(3) Loosened back plate or the support installing
bolts
(4) Loose wheel bearing
(5) Dirty drum or rotor
6. Brake noise (2) (1) Worn lining
(hissing sound)
(2) Improper installed shoe or pad
(3) Loose or bent drum or rotor
GENERAL DIAGNOSTICS
Trouble and possible cause
BR-78
Corrective action
Repair or replace (cup, piston seal, piston boot,
master cylinder piston kit, pipe or hose).
Bleed the air.
Adjust the clearance.
Replace, grind or clean.
Correct or replace.
Eliminate cause of fluid leakage, clean, or replace.
Correct or replace the drum or rotor.
Correct by grinding, or replace.
Correct by grinding, or replace.
Correct or replace.
Inflate to correct pressure.
Adjust alignment.
Retighten.
Retighten to normal tightening torque or replace.
Replace the cylinder, brake pipe or hose.
Check, adjust, or replace the rear brake and cable
system.
Bleed the air.
Adjust.
Repair or replace (cup, piston seal, piston boot,
master cylinder piston kit, pipe or hose).
Adjust.
Correct or replace.
Adjust play.
Clean or replace the cylinder.
Replace.
Replace the spring.
Adjust the clearance.
Correct or replace.
Replace the wheel bearing.
Replace the shoe assembly or pad.
Replace the shoe assembly or pad.
Retighten.
Retighten to normal tightening torque.
Clean the drum or rotor, or clean and replace the
brake assembly.
Replace the shoe assembly or pad.
Correct or replace the shoe assembly or pad.
Retighten or replace.