TROUBLESHOOTING (Cont'd) Problem | Possible cause | Remedy | Page Squealing, groaning or chattering noise when brakes are applied Note: Brake friction materials inherently generate noise and heat in order to dissipate energy. As a result, occasional squeal is normal and is aggravated by severe environmental conditions such as cold, heat, wetness, snow, salt, mud, etc. This occasional squeal is not a functional problem and does not indicate any loss of brake effectiveness Rotors and pads worn or scored | Inspect, service or replace | BR-14,20 Disc brakes—missing or damaged brake pad anti-squeal shim | Replace | BR-14,20 Disc brakes—burred or rusted calipers | Clean or deburr | BR-16,22 Dirty, greased, contaminated or glazed linings | Clean or replace | BR-14,20 Improper lining parts | Inspect for correct usage, replace | BR-14,20 Mal-adjustment of brake pedal or booster push-rod | Inspect and adjust | BR-6,12 Loose or damaged shoe retaining pins, springs and clips and grooved backing plate ledges | Inspect, service or replace | BR-26 Pad wear and pad wear indicator making contact with the rotor | Replace | BR-14,20 Squealing noise when brakes are not applied Bent or warped backing plate causing interference with drum | Service or replace | BR-26 Improper machining of drum causing interference with backing plate or shoe | Replace drum | BR-26 Mal-adjustment of brake pedal or booster push-rod | Inspect and adjust | BR-6,12 Poor return of brake booster or master cylinder | Inspect, service or replace | BR-9,12 14,20 Disc brake—rusted, stuck | Inspect, lubricate as necessary | BR-14,20 Other brake system components: Loose or extra parts in brakes | Inspect, service, replace as required | BR-26 Rear drum adjustment too tight causing lining to glaze Worn, damaged or insufficiently lubricated wheel bearings Drum brakes—weak, damaged or incorrect shoe hold-down springs | | BR-26 Drum brakes—grooved backing plate ledges | | BR-26 Improper positioning of pad in caliper | | BR-14,20 Outside diameter of rotor rubbing caliper housing Housing installation of disc brake pad support plate | | BR-14,20 Pad wear and pad wear indicator making contact with the rotor | | BR-14,20