34 90... Troubleshooting brake system
TROUBLESHOOTING CHART
| Fault | Cause | Remedy |
|---|---|---|
| Brakes pull to one side | a) Tyre inflation pressure not in keeping with regulations | a) Correct tire inflation pressure |
| b) Unevenly worn tire treads | b) Change or replace tires | |
| c) Oil on pads/liners | c) Replace brake pads , Check for causes | |
| d) Wrong type of pads/liners | d) Replace brake pads , Check for causes | |
| f) Guide bolts dirty or damaged | f) Replace guide bolts | |
| g) Axle geometry not correct | g) Check wheel alignment | |
| h) Corrosion in floating calipers | h) Remove and install, repair or replace floating calipers | |
| i) No shock absorber action | i) Check shock absorbers, replace if necessary | |
| k) Pad of one caliper worn | k) Replace brake pads , check floating caliper | |
| Brakes excessively hot while driving | a) Compensating port in brake master cylinder blocked | a) Replace master brake cylinder |
| c) Swollen rubber parts due to use of wrong brake fluid | c) Replace master brake cylinder | |
| d) Bleeder hole on expansion tank blocked | d) Clean expansion tank | |
| e) Corroded floating calipers | e) Remove and install, repair or replace floating calipers | |
| f) Handbrake lever not released fully | f) Check handbrake and handbrake Bowden cables, repair if necessary | |
| 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 sparingly | a) Air in brake system | a) Bleed brakes See Bleeding brake system with DSC. |
| b) Not enough brake fluid in expansion tank | b) Top up or change brake fluid Bleed brakes See Bleeding brake system with DSC. | |
| c) Overheated brake fluid - vapor lock due to excessive water content in brake fluid or excessive brake loads | c) Change brake fluid, Bleed brakes See Bleeding brake system with DSC. | |
| Brake is bled and readjusted, but brake pedal can be pressed down too far | a) Primary cup seal in brake master cylinder damaged | a) Replace master brake cylinder |
| b) Leaking separating cup seals on floating piston of brake master cylinder | b) Replace master brake cylinder | |
| c) Leak in brake system | c) Leakage test of brake system | |
| Uneven pad wear | a) Wrong type of pads/liners | a) Replace brake pads |
| b) Dirty floating caliper recesses, damaged caps | b) Remove and install, repair or replace floating calipers | |
| c) Corrosion in floating calipers | c) Remove and install, repair or replace floating calipers | |
| d) Swollen rubber ring for piston control | d) Remove and install, repair or replace floating calipers | |
| Brake pads worn at angle | a) Wheel-bearing play excessive | a) Replace wheel bearings |
| b) Brake disc not aligned with floating caliper | b) Check floating caliper installation | |
| c) Corrosion in floating calipers | c) Remove and install, repair or replace floating calipers | |
| d) Angular brake-disc wear | d) Replace brake discs | |
| e) Minimum pad thickness undershot | e) Replace brake pads | |
| f) Spring force insufficient | f) Replace spring | |
| g) Guide bolts damaged | g) Replace guide bolts | |
| Seized brake pads, pad does not move off brake disc | a) Dirty floating caliper recesses, damaged caps | a) Remove and install, repair or replace floating calipers |
| b) Corrosion in floating calipers | b) Remove and install, repair or replace floating calipers | |
| c) Compensating port in brake master cylinder blocked | c) Replace master brake cylinder | |
| Brakes squeal or rattle | a) Wrong type of pads/liners | a) Replace brake pads |
| b) Dirty floating caliper recesses | b) Remove and install/clean floating calipers | |
| c) Spring force insufficient | c) Replace spring | |
| d) Brake disc not aligned with floating caliper | d) Check floating caliper installation | |
| e) Brake-disc runout | e) Replace brake discs | |
| f) Excessive thickness deviation within braking surface | f) Measure brake disc thickness Replace discs | |
| g) Liner wear excessive or one-sided | g) Replace brake shoes | |
| h) Rust edges on brake discs | h) Replace brake discs | |
| i) Pad loose | i) Replace brake pads | |
| j) Wheel-bearing play excessive | j) Replace wheel bearings | |
| Brake-pedal dead travel excessive | a) Wheel-bearing play excessive | a) Replace wheel bearings |
| b) Brake disc not aligned with floating caliper | b) Check floating caliper installation | |
| c) Brake-disc runout | c) Replace brake discs | |
| d) Excessive thickness deviation within braking surface | d) Measure brake disc thickness Replace discs | |
| e) Brake system leaking | e) Leakage test of brake system | |
| f) Air in brake system | f) Bleed brakes See Bleeding brake system with DSC. | |
| g) Wrong type of pads/liners | g) Replace brake pads | |
| Jammed piston in brake caliper | a) Dirty floating caliper recesses, damaged caps | a) Remove and install, repair or replace floating caliper |
| b) Brake disc not aligned with floating caliper | b) Check floating caliper installation | |
| c) Pistons corroded in floating calipers | c) Remove and install, repair or replace floating caliper | |
| Pulsating effect on brake pedal | a) Wheel-bearing play excessive | a) Replace wheel bearings |
| b) Brake disc not aligned with floating caliper | b) Check floating caliper installation | |
| c) Brake-disc runout | c) Replace brake discs | |
| d) Excessive thickness deviation within braking surface | d) Measure brake disc thickness Replace discs | |
| Handbrake effect insufficient | a) Brake pad fouled by oil | a) Replace brake pads , determine cause |
| b) Excessive free play | b) adjust handbrake. | |
| c) Corroded transmitting elements | c) Remove and install handbrake, check brake caliper, Bowden cables, replace if necessary |