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34 90 ... Troubleshooting brake system

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TROUBLESHOOTING CHART

Fault Cause Remedy
Brakes pull to one side
  1. a) Tyre inflation pressure not in keeping with regulations
  2. b) Unevenly worn tyre treads
  3. c) Oil on pads/liners
  4. d) Wrong type of pads/liners
  5. f) Guide bolts dirty or damaged
  6. g) Axle geometry not correct
  7. h) Corrosion in floating calipers
  8. i) No shock absorber action
  9. k) Pad of one caliper worn
  1. a) Correct tyre inflation pressure
  2. b) Change or Replace Tyres
  3. c) Replace Brake Pads , Check for causes
  4. d) Replace Brake Pads , Check for causes
  5. f) Replace Guide Bolts 
  6. g) Check Wheel Alignment
  7. h) Remove and install, repair or replace Floating Calipers 
  8. i) Check shock absorber, Replacing If Necessary
  9. k) Replace Brake Pads , check floating caliper
Brakes excessively hot while driving
  1. a) Compensating port in brake master cylinder blocked
  2. c) Swollen rubber parts due to use of wrong brake fluid
  3. d) Bleeder hole on expansion tank blocked
  4. e) Corroded floating calipers
  5. f) Handbrake lever not released fully
  1. a) ReplaceMaster Brake Cylinder 
  2. c) Replace Master Brake Cylinder 
  3. d) Clean Expansion Tank 
  4. e) Remove and install, repair or replace Floating Calipers 
  5. 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
  1. Air in brake system
  2. Not enough brake fluid in expansion tank
  3. Overheated brake fluid - vapour lock due to excessive water content in brake fluid or excessive brake loads
  1. Bleed brakes 
  2. Top up or change brake fluid Bleed brakes 
  3. Change brake fluid, Bleed brakes 
Brake is bled and readjusted, but brake pedal can be pressed down too far
  1. Primary cup seal in brake master cylinder damaged
  2. Leaking separating cup seals on floating piston of brake master cylinder
  3. Leak in brake system
  1. Replace Master Brake Cylinder 
  2. Replace Master Brake Cylinder 
  3. Leakage test of brake system
TROUBLESHOOTING CHART

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

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

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