34 90 ... Troubleshooting brake system

TROUBLESHOOTING CHART

Fault	Cause	Remedy
Brakes pull to one side	a) Tyre inflation pressure not in keeping with regulations b) Unevenly worn tyre treads c) Oil on pads/liners d) Wrong type of pads/liners f) Guide bolts dirty or damaged g) Axle geometry not correct h) Corrosion in floating calipers i) No shock absorber action k) Pad of one caliper worn	a) Correct tyre inflation pressure b) Change or Replace Tyres c) Replace Brake Pads , Check for causes d) Replace Brake Pads , Check for causes f) Replace Guide Bolts g) Check Wheel Alignment h) Remove and install, repair or replace Floating Calipers i) Check shock absorber, Replacing If Necessary k) Replace Brake Pads , check floating caliper
Brakes excessively hot while driving	a) Compensating port in brake master cylinder blocked c) Swollen rubber parts due to use of wrong brake fluid d) Bleeder hole on expansion tank blocked e) Corroded floating calipers f) Handbrake lever not released fully	a) ReplaceMaster Brake Cylinder c) Replace Master Brake Cylinder d) Clean Expansion Tank e) Remove and install, repair or replace Floating Calipers f) Check handbrake and handbrake Bowden cables, Repair If Necessary

TROUBLESHOOTING CHART

Fault	Cause	Remedy
Poor braking effect in spite of great force on pedal Travel at brake pedal normal	Brake pads oil-splattered or burnt; wrong type of brake pads	Replace Brake Pads
Poor braking effect in spite of great force on pedal Travel at brake pedal too short	Brake booster malfunctions - engine vacuum	Check brake booster
Poor braking effect in spite of great force on pedal Travel at brake pedal too long	One brake circuit failed due to leaks or damage	Leakage test of brake system
Brake pedal can be pressed down softly and springily	Air in brake system Not enough brake fluid in expansion tank Overheated brake fluid - vapour lock due to excessive water content in brake fluid or excessive brake loads	Bleed brakes Top up or change brake fluid Bleed brakes Change brake fluid, Bleed brakes
Brake is bled and readjusted, but brake pedal can be pressed down too far	Primary cup seal in brake master cylinder damaged Leaking separating cup seals on floating piston of brake master cylinder Leak in brake system	Replace Master Brake Cylinder Replace Master Brake Cylinder Leakage test of brake system

TROUBLESHOOTING CHART

Fault	Cause	Remedy
Uneven pad wear	Wrong type of pads/liners Dirty fist caliper recesses, damaged caps Corrosion in floating calipers Swollen rubber ring for piston control	Replace Brake Pads Remove and install, repair or replace Floating Calipers Remove and install, repair or replace Floating Calipers Remove and install, repair or replace Floating Calipers
Brake pads worn at angle	Wheel-bearing play excessive Brake disk not aligned with fist caliper Corrosion in floating calipers Angular brake-disk wear Minimum lining thickness undershot Spring force insufficient Guide bolts damaged	Replace Wheel Bearings Check floating caliper installation Remove and install, repair or replace Floating Calipers Grind or replace Brake Disks Replace Brake Pads Replace Spring Replace Guide Bolts
Seized brake pads, pad does not move off brake disk	Dirty fist caliper recesses, damaged caps Corrosion in floating calipers Compensating port in brake master cylinder blocked	Remove and install, repair or replace Floating Calipers Remove and install, repair or replace Floating Calipers Replace Master Brake Cylinder

TROUBLESHOOTING CHART

Fault	Cause	Remedy
Brakes squeal or rattle	Wrong type of pads/liners Dirty floating caliper recesses Spring force insufficient Brake disk not aligned with fist caliper Brake-disk runout Excessive thickness deviation within braking surface Liner wear excessive or one-sided Rust edges on brake disks Pad loose Wheel-bearing play excessive	Replace Brake Pads Remove and install/clean Floating Calipers Replace Spring Check floating Caliper Installation Replace brake Disks Measure brake disk thickness Grind or replace Disks Replace Brake Shoes Grind or replace brake Disks Replace Brake Pads Replace Wheel Bearings
Brake-pedal dead travel excessive	Wheel-bearing play excessive Brake disk not aligned with fist caliper Brake-disk runout Excessive thickness deviation within braking surface Brake system leaking Air in brake system Wrong type of pads/liners	Replace Wheel Bearings Check Floating Calipers installation Replace brake Disks Measure brake disk thickness Grind or replace Disks Leakage test of brake system Bleed Brakes Replace Brake Pads

TROUBLESHOOTING CHART

Fault	Cause	Remedy
Jammed piston in brake caliper	Dirty fist caliper recesses, damaged caps Brake disk not aligned with fist caliper Pistons corroded in floating calipers	Remove and install, repair or replace Floating Calipers Check Floating Calipers installation Remove and install, repair or replace Floating Calipers
Pulsating effect on brake pedal	Wheel-bearing play excessive Brake disk not aligned with fist caliper Brake-disk runout Excessive thickness deviation within braking surface	Replace Wheel Bearings Check Floating Calipers installation Replace brake Disks Measure brake disk thickness Grind or replace Disks
Handbrake effect insufficient	Brake shoes oil-splattered Excessive dead travel between brake shoes and brake drums Corroded transmitting elements	Replace Brake Shoes , determine cause Adjust Handbrake Remove and install handbrake and expander locks Check Bowden cables , replacing if necessary