34 90 ... Troubleshooting Brake System
WARNING: This page is about a different car, the 2010 BMW X5, 2009 BMW X5, 2008 BMW X5, and 2007 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.
Troubleshooting brake system
| 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 tires. See 36 12 001 REPLACING A TIRE , 36 12 005 REPLACING A RUNFLAT TIRE c) Replace brake pad. See 34 11 000 Removing and Installing/Replacing Brake Linings On Both Front Disc Brakes , 34 21 200 Removing and Installing/Replacing Brake Linings On Both Rear Disc Brakes (Teves Floating Caliper) . Check for causes d) Replace brake pads. See 34 11 000 Removing and Installing/Replacing Brake Linings On Both Front Disc Brakes , 34 21 200 Removing and Installing/Replacing Brake Linings On Both Rear Disc Brakes (Teves Floating Caliper) f) Replace guide bolts. See 34 11 000 Removing and Installing/Replacing Brake Linings On Both Front Disc Brakes , 34 21 200 Removing and Installing/Replacing Brake Linings On Both Rear Disc Brakes (Teves Floating Caliper) g) Check wheel alignment. See 32 00 ... CHASSIS/WHEEL ALIGNMENT CHECK PROCEDURE , 32 00 150 KDS CHASSIS/WHEEL ALIGNMENT CHECK WITH LOAD UP TO DESIGN POSITION , 32 00 155 KDS CHASSIS/WHEEL ALIGNMENT CHECK WITH RIDE-HEIGHT MEASUREMENT WITHOUT LOAD h) Remove and install, repair or replace floating calipers. See 34 11 000 Removing and Installing/Replacing Brake Linings On Both Front Disc Brakes , 34 11 552 Overhauling Left Or Right Front Brake Caliper (Brake Caliper Removed) i) Check shock absorber, replacing if necessary. See 31 31 031 REPLACING FRONT LEFT OR RIGHT SPRING STRUT SHOCK ABSORBER , 33 52 000 REMOVING AND INSTALLING/REPLACING REAR LEFT OR RIGHT SHOCK ABSORBER k) Replace brake pads, check floating caliper. See 34 11 000 Removing and Installing/Replacing Brake Linings On Both Front Disc Brakes , 34 21 200 Removing and Installing/Replacing Brake Linings On Both Rear Disc Brakes (Teves 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) Replace brake master cylinder 34 31 505 Removing and Installing / Replacing Master Brake Cylinder for DSC c) Replace brake master cylinder 34 31 505 Removing and Installing / Replacing Master Brake Cylinder for DSC d) Clean expansion tank 34 31 181 Removing and Installing / Replacing Expansion Tank For Hydraulic Brake Actuation e) Remove and install, repair or replace floating calipers 34 11 519 Removing and Installing/Replacing Left Or Right Front Brake Caliper , 34 11 552 Overhauling Left Or Right Front Brake Caliper (Brake Caliper Removed) f) Check handbrake and handbrake Bowden cables, repair if necessary. 34 41 280 Removing and Installing/Replacing Actuating Unit With Control Unit For Parking Brake (EMF) |
| 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. See 34 11 000 Removing and Installing/Replacing Brake Linings On Both Front Disc Brakes |
| 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. See 34 00 519 Checking Service Brake: High- And Low-Pressure Tests |
| Brake pedal can be pressed down softly and springily | a) Air in brake system b) Not enough brake fluid in expansion tank c) Overheated brake fluid - vapour lock due to excessive water content in brake fluid or excessive brake loads |
a) Bleed brakes. See 34 00 050 Bleeding Brake System with DSC b) Top up or change brake fluid Bleed brakes. See 34 00 050 Bleeding Brake System with DSC c) Change brake fluid, Bleed brakes. See 34 00 050 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 b) Leaking separating cup seals on floating piston of brake master cylinder c) Leak in brake system |
a) Replace master brake cylinder. See 34 31 505 Removing and Installing / Replacing Master Brake Cylinder for DSC b) Replace master brake cylinder. See 34 31 505 Removing and Installing / Replacing Master Brake Cylinder for DSC c) Leakage test of brake system. See 34 00 519 Checking Service Brake: High- And Low-Pressure Tests |
| Brake pedal can be pressed down softly and springily | a) Air in brake system b) Not enough brake fluid in expansion tank c) Overheated brake fluid - vapour lock due to excessive water content in brake fluid or excessive brake loads |
a) Bleed brakes. See 34 00 050 Bleeding Brake System with DSC b) Top up or change brake fluid Bleed brakes. See 34 00 050 Bleeding Brake System with DSC c) Change brake fluid, Bleed brakes. See 34 00 050 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 b) Leaking separating cup seals on floating piston of brake master cylinder c) Leak in brake system |
a) Replace master brake cylinder. See 34 31 505 Removing and Installing / Replacing Master Brake Cylinder for DSC b) Replace master brake cylinder. See 34 31 505 Removing and Installing / Replacing Master Brake Cylinder for DSC c) Leakage test of brake system. See 34 00 050 Bleeding Brake System with DSC |
| Fault | Cause | Remedy |
| Uneven pad wear | a) Wrong type of pads/liners b) Dirty floating caliper recesses, damaged caps c) Corrosion in floating calipers d) Swollen rubber ring for piston control |
a) Replace brake pads. See 34 11 000 Removing and Installing/Replacing Brake Linings On Both Front Disc Brakes b) Remove and install, repair or replace floating calipers. See 34 11 519 Removing and Installing/Replacing Left Or Right Front Brake Caliper c) Remove and install, repair or replace floating calipers. See 34 11 519 Removing and Installing/Replacing Left Or Right Front Brake Caliper d) Remove and install, repair or replace floating calipers. See 34 11 519 Removing and Installing/Replacing Left Or Right Front Brake Caliper |
| Brake pads worn at angle | a) Wheel-bearing play excessive b) Brake disc not aligned with floating caliper c) Corrosion in floating calipers d) Angular brake-disc wear e) Minimum pad thickness undershot f) Spring force insufficient g) Guide bolts damaged |
a) Replace wheel bearings. See 33 41 151 REPLACING LEFT OR RIGHT WHEEL BEARING ON REAR AXLE SHAFT b) Check floating caliper installation c) Remove and install, repair or replace floating calipers. See 34 11 519 Removing and Installing/Replacing Left Or Right Front Brake Caliper d) Grind or replace brake disks. See 34 11 220 Removing and Installing/Replacing Both Front Brake Discs e) Replace brake pads. See 34 11 000 Removing and Installing/Replacing Brake Linings On Both Front Disc Brakes f) Replace spring. See 34 11 000 Removing and Installing/Replacing Brake Linings On Both Front Disc Brakes g) Replace guide bolts. See 34 11 000 Removing and Installing/Replacing Brake Linings On Both Front Disc Brakes |
| Seized brake pads, pad does not move off brake disc | a) Dirty floating caliper recesses, damaged caps b) Corrosion in floating calipers c) Compensating port in brake master cylinder blocked |
a) Remove and install, repair or replace floating calipers. See 34 11 519 Removing and Installing/Replacing Left Or Right Front Brake Caliper b) Remove and install, repair or replace floating calipers. See 34 11 519 Removing and Installing/Replacing Left Or Right Front Brake Caliper c) Replace master brake cylinder. See 34 31 505 Removing and Installing / Replacing Master Brake Cylinder for DSC |
| Fault | Cause | Remedy |
| Brakes squeal or rattle | a) Wrong type of pads/liners b) Dirty floating caliper recesses c) Spring force insufficient d) Brake disc not aligned with floating caliper e) Brake-disc runout f) Excessive thickness deviation within braking surface g) Liner wear excessive or one-sided h) Rust edges on brake discs i) Pad loose j) Wheel-bearing play excessive |
a) Replace brake pads. See 34 11 000 Removing and Installing/Replacing Brake Linings On Both Front Disc Brakes b) Remove and install/clean floating calipers. See 34 11 519 Removing and Installing/Replacing Left Or Right Front Brake Caliper c) Replace spring. See 34 11 000 Removing and Installing/Replacing Brake Linings On Both Front Disc Brakes d) Check floating caliper installation. See 34 11 519 Removing and Installing/Replacing Left Or Right Front Brake Caliper e) Replace brake discs. See 34 11 220 Removing and Installing/Replacing Both Front Brake Discs f) Measure brake disc thickness Grind or replace disks. See34 11 667 Precision-turning Both Front Brake Discs On Both Sides g) Replace brake shoes. See 34 41 220 Removing and Installing/Replacing All Handbrake Shoes h) Grind or replace brake disks. See 34 11 667 Precision-turning Both Front Brake Discs On Both Sides i) Replace brake pads. See 34 11 000 Removing and Installing/Replacing Brake Linings On Both Front Disc Brakes j) Replace wheel bearings. See 33 41 151 REPLACING LEFT OR RIGHT WHEEL BEARING ON REAR AXLE SHAFT |
| Brake-pedal dead travel excessive | a) Wheel-bearing play excessive b) Brake disc not aligned with floating caliper c) Brake-disc runout d) Excessive thickness deviation within braking surface e) Brake system leaking f) Air in brake system g) Wrong type of pads/liners |
a) Replace wheel bearings. See 33 41 151 REPLACING LEFT OR RIGHT WHEEL BEARING ON REAR AXLE SHAFT b) Check floating caliper installation c) Replace brake discs. See 34 11 220 Removing and Installing/Replacing Both Front Brake Discs d) Measure brake disc thickness Grind or replace disks. See 34 11 667 Precision-turning Both Front Brake Discs On Both Sides e) Leakage test of brake system. See 34 00 519 Checking Service Brake: High- And Low-Pressure Tests f) Bleed brakes 34 00 519 Checking Service Brake: High- And Low-Pressure Tests g) Replace brake pads. See 34 11 000 Removing and Installing/Replacing Brake Linings On Both Front Disc Brakes |
| Fault | Cause | Remedy |
| Jammed piston in brake caliper | a) Dirty floating caliper recesses, damaged caps b) Brake disc not aligned with floating caliper c) Pistons corroded in floating calipers |
a) Remove and install, repair or replace floating caliper. See 34 11 519 Removing and Installing/Replacing Left Or Right Front Brake Caliper b) Check floating caliper installation. See 34 11 519 Removing and Installing/Replacing Left Or Right Front Brake Caliper c) Remove and install, repair or replace floating caliper. See 34 11 519 Removing and Installing/Replacing Left Or Right Front Brake Caliper |
| Pulsating effect on brake pedal | a) Wheel-bearing play excessive b) Brake disc not aligned with floating caliper c) Brake-disc runout d) Excessive thickness deviation within braking surface |
a) Replace wheel bearings. See 31 21 180 REPLACING BEARING (WHEEL BEARING) FOR FRONT WHEEL b) Check floating caliper installation. See 34 11 519 Removing and Installing/Replacing Left Or Right Front Brake Caliper c) Replace brake discs. See 34 11 220 Removing and Installing/Replacing Both Front Brake Discs d) Measure brake disc thickness Grind or replace disks. See 34 11 667 Precision-turning Both Front Brake Discs On Both Sides |
| Handbrake effect insufficient | a) Brake shoes oil-splattered b) Excessive dead travel between brake shoes and brake drums c) Corroded transmitting elements |
a) Replace brake shoes. See 34 41 220 Removing and Installing/Replacing All Handbrake Shoes determine cause b) Adjust handbrake. See 34 41 006 Adjusting Parking Brake c) Remove and install handbrake and expander locks Check Bowden cables, replacing if necessary. See 34 41 280 Removing and Installing/Replacing Actuating Unit With Control Unit For Parking Brake (EMF) |