Table 11.2. Diagnostics of malfunctions of the brake system
Fault | Cause of failure | Troubleshooting |
Uneven action of the brake mechanisms of the wheels of one axle | A) Tire pressure not correct | A) adjust tire pressure |
b) uneven tread pattern wear | b) swap tires replace tires | |
V) oiling brake pads | V) replace brake pads, find out the cause | |
G) wrong pad type | G) replace brake pads, find out the cause | |
d) contamination of the grooves of the floating caliper | d) remove and clean floating calipers | |
e) dirty or damaged guide pins | e) replace guide pins | |
and) incorrect rear suspension geometry | and) measure wheel alignment | |
h) corrosive damage to floating calipers or wheel brake cylinders | h) remove calipers or wheel brake cylinders, repair or replace them | |
And) shock absorber malfunction | And) check shock absorber, replace if necessary | |
To) wear on the lining of one of the calipers | To) replace brake pads check floating caliper | |
l) insufficient roughness of linings | l) replace brake pads, check floating caliper | |
Strong heating of the brakes while driving | A) blockage of the compensation hole in the master cylinder | A) overhaul the brake master cylinder, replace if necessary |
b) no clearance between master cylinder piston and rod | b) adjust stem (on old cars) | |
V) swelling of rubber parts due to the use of the wrong brand of brake fluid | V) overhaul the brake master cylinder, replace if necessary | |
G) clogged vent hole in master cylinder reservoir | G) clean the master cylinder reservoir | |
d) floating caliper corrosion | d) remove floating calipers, repair or replace them | |
e) expansion spring broken | e) replace expansion spring | |
and) parking brake not fully released | and) check the parking brake and its cables, repair if necessary | |
Poor service brake action despite increased brake pedal pressure. Normal brake pedal travel | oily or burnt brake pads, wrong type of pads | replace brake pads |
Poor service brake action despite increased brake pedal pressure. Short travel of the brake pedal | the amplifier does not work - the discharge created by the engine is not enough | check brake booster - check engine (valves, cylinder head gasket, etc.) |
Poor service brake action despite increased brake pedal pressure. Increased pedal travel | failure of the brake drive circuit due to depressurization or damage | check the tightness of the brake system |
The brake pedal falls off | A) air in the brake system | A) add or replace brake fluid, bleed the brake system |
b) not enough brake fluid in the reservoir - as a) | b) add or replace brake fluid, bleed the brake system | |
V) brake fluid overheating (steam bubbles) due to increased water content in the brake fluid or brake overload | V) add or replace brake fluid, bleed the brake system | |
The hydraulic brake actuator has been bled and the system is adjusted, but the brake pedal fails | A) damage to the primary cuff of the master cylinder | A) overhaul or replace brake master cylinder |
b) leakage of the intermediate cuff on the floating piston of the two-cavity master brake cylinder | b) overhaul or replace brake master cylinder | |
V) leak in the brake system | V) check the tightness of the brake system | |
Uneven brake pad wear | A) wrong pad type | A) replace brake pads |
b) contamination of the grooves of the floating caliper, damage to the protective covers | b) remove calipers or wheel brake cylinders, repair or replace them | |
V) corrosive damage to floating calipers or wheel brake cylinders | V) remove calipers or wheel brake cylinders, repair or replace them | |
G) swelling of the rubber adjusting piston ring | G) remove calipers or wheel brake cylinders, repair or replace them | |
One-sided brake pad wear | A) increased wheel bearing clearance | A) replace wheel bearing |
b) brake disc and floating caliper mounting misalignment | b) check floating caliper mounting | |
V) corrosive damage to floating calipers or wheel brake cylinders | V) remove calipers or wheel brake cylinders, repair or replace them | |
G) one-sided brake disc wear | G) grind or replace brake discs | |
d) thickness of brake pads is less than the minimum allowable | d) replace brake pads | |
e) insufficient retaining spring pressure | e) replace retaining spring | |
and) guide pin damage | and) replace guide pins | |
Adhesion of brake pads to the brake disc | A) contamination of the grooves of the floating caliper, damage to the protective covers | A) remove floating calipers, repair or replace them |
b) floating caliper corrosion | b) remove floating calipers, repair or replace them | |
V) blockage of the compensation hole in the master cylinder | V) overhaul or replace brake master cylinder | |
Screeching and crackling brakes | A) wrong pad type | A) replace brake pads |
b) contamination of the grooves of the floating caliper | b) remove and clean floating calipers | |
V) insufficient retaining spring pressure | V) replace retaining spring | |
G) brake disc misalignment and | G) check floating caliper mounting | |
d) brake disc runout | d) check the brake discs for runout and replace them if necessary | |
e) the disc thickness difference within the working surface is above the allowable | e) measure brake disc thickness, grind or replace discs | |
and) out-of-roundness of brake drums | and) grind or replace brake drums | |
h) brake drum beat | h) grind or replace brake drums | |
And) dirt and dust in the brake drums | And) clean and check brake drums | |
To) increased or one-sided pad wear | To) replace parking brake pads | |
l) rusted edges of brake discs | l) grind or replace brake discs | |
m) block is not fixed | m) replace brake pads | |
n) increased wheel bearing clearance | n) replace wheel bearing | |
Increased brake pedal free play | A) increased wheel bearing clearance | A) replace wheel bearing |
b) brake disc and floating caliper mounting misalignment | b) check floating caliper mounting | |
V) brake disc runout | V) check the brake discs for runout and replace them if necessary | |
G) the disc thickness difference within the working surface is above the allowable | G) measure brake disc thickness, grind or replace discs | |
d) brake system leaking | d) check the tightness of the brake system | |
e) air in the brake system | e) bleed the brake system | |
and) wrong pad type | and) replace the brake pads or replace the parking brake pads | |
h) automatic brake pad adjustment not working | h) remove parking brake pads restore adjustment | |
Piston stuck in caliper | A) contamination of the grooves of the floating caliper, damage to the protective covers | A) remove floating calipers, repair or replace them |
b) brake disc and floating caliper mounting misalignment | b) check floating caliper mounting | |
V) corrosion of pistons in floating calipers or wheel brake cylinders | V) remove the caliper or wheel brake cylinder, repair or replace it | |
Pulsation of the brake pedal | A) increased wheel bearing clearance | A) replace wheel bearing |
b) brake disc and floating caliper mounting misalignment | b) replace floating caliper mount | |
V) brake disc runout | V) replace brake discs | |
G) the disc thickness difference within the working surface is above the allowable | G) measure brake disc thickness, grind or replace discs | |
Insufficient effectiveness of the parking brake | A) oiling brake pads | A) replace brake pads, determine the cause |
b) increased free play between brake pads and brake drum | b) adjust parking brake | |
V) increased cable free play | V) adjust parking brake | |
G) incorrect cable adjustment | G) adjust parking brake | |
d) transmission elements corrosion | d) remove the parking brake and spreaders, check and, if necessary, replace the cables |