34 90... Troubleshooting brake system
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2013 BMW 128i, 2012 BMW 128i, 2011 BMW 128i, 2010 BMW 128i, and 2009 BMW 128i. However, it is still accessible from the selected car via links, so may be relevant.
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 absorber, replacing 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 brake master cylinder |
| c) Swollen rubber parts due to use of wrong brake fluid | c) Replace brake master 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 |
BRAKE SYSTEM 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 | a) Air in brake system | a) Bleed brakes |
| b) Not enough brake fluid in expansion tank | b) Top up or change brake fluid Bleed brakes |
|
| c) Overheated brake fluid - vapor lock due to excessive water content in brake fluid or excessive brake loads | c) Change brake fluid, Bleed brakes | |
| 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 |
BRAKE SYSTEM TROUBLESHOOTING CHART
| Fault | Cause | Remedy |
|---|---|---|
| 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) Grind or replace brake disks | |
| 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 |
BRAKE SYSTEM TROUBLESHOOTING CHART
| Fault | Cause | Remedy |
|---|---|---|
| Brakes squeal or rattle | a) Wrong type of pads/liners | a) Replace brake linings |
| 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 Grind or replace disks | |
| g) Liner wear excessive or onesided | g) Replace brake shoes | |
| h) Rust edges on brake discs | h) Grind or replace brake disks | |
| 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 Grind or replace disks | |
| e) Brake system leaking | e) Leakage test of brake system | |
| f) Air in brake system | f) Bleed brakes | |
| g) Wrong type of pads/liners | g) Replace brake pads |
BRAKE SYSTEM TROUBLESHOOTING CHART
| Fault | Cause | Remedy |
|---|---|---|
| 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 Grind or replace disks | |
| Handbrake effect insufficient | a) Brake shoes oil-splattered | a) Replace brake shoes , determine cause |
| b) Excessive dead travel between brake shoes and brake drums | b) Adjust handbrake | |
| c) Corroded transmitting elements | c) Remove and install handbrake and expander locks Check Bowden cables, replacing if necessary |