General Diagnostic Table: Inspection

WARNING: This page is about a different car, the 2021 Subaru Ascent. However, it is still accessible from the selected car via links, so may be relevant.

Trouble and possible cause		Corrective action
Insufficient braking	(1) Fluid leakage from the hydraulic mechanism	Repair or replace. (Cup, piston seal, boot piston, master cylinder piston kit, brake pipe or brake hose)
	(2) Entry of air into the hydraulic mechanism	Bleed air.
	(3) Wear, deteriorated surface material, water or fluid on pad	Replace, grind or clean.
	(4) Improper operation of master cylinder assembly, brake caliper, vacuum booster assembly or check valve	Repair or replace.
Unstable or uneven braking	(1) Fluid on pad surface or brake disc	Correct the cause of fluid leakage, and clean or replace.
	(2) Defective brake disc	Repair or replace the brake disc.
	(3) Improper pad contact, deteriorated surface, deteriorated or worn pad material	Repair by grinding, or replace.
	(4) Deformed brake back plate	Repair or replace.
	(5) Over inflation of tires	Adjust the air pressure.
	(6) Defective wheel alignment	Adjust alignment.
	(7) Loose support installation bolt	Tighten to the specified torque.
	(8) Defective hub unit bearing	Replace.
	(9) Defective hydraulic system	Replace the cylinder, brake pipe or brake hose.
	(10) Unstable performance of the parking brake	Check, adjust or replace the rear brake.
Excessive pedal stroke	(1) Entry of air into the hydraulic mechanism	Bleed air.
	(2) Excessive play in the master cylinder push rod	Adjust.
	(3) Fluid leakage from the hydraulic mechanism	Repair or replace. (Cup, piston seal, boot piston, master cylinder piston kit, brake pipe or brake hose)
	(4) Improper pad contact or worn pad	Repair or replace.
Brake dragging or improper brake return	(1) Insufficient pedal play	Adjust play.
	(2) Improper master cylinder return	Clean or replace the cylinder.
	(3) Clogged hydraulic system	Replace.
	(4) Improper return of parking brake	Repair or adjust.
	(5) Improper brake caliper operation	Repair or replace.
	(6) Defective hub unit bearing	Replace.
Brake noise (1) (creaking sound)	(1) Hardened or deteriorated brake pad	Replace the brake pad.
	(2) Worn brake pad	Replace the brake pad.
	(3) Loose brake disc or support installation bolt	Tighten to the specified torque.
	(4) Loose hub unit bearing	Tighten to the specified torque.
	(5) Dirt on brake disc	Clean the brake disc. Clean and replace brake assembly.
Brake noise (2) (hissing sound)	(1) Worn brake pad	Replace the brake pad.
	(2) Improperly installed brake pad	Correct or replace the brake pad.
	(3) Loose or bent brake disc	Retighten or replace.
Brake noise (3) (click sound)	Excessively worn brake pad or support	Replace the brake pad or the support.