34 90 ... Troubleshooting brake system

WARNING: This page is about a different car, the 2010 BMW M3, 2009 BMW M3, and 2008 BMW M3. However, it is still accessible from the selected car via links, so may be relevant.

TROUBLESHOOTING CHART

Fault	Cause	Remedy
Brake squeaks	1. Fouled brake system	Remove and install, clean and grease brake calipers Clean and grease brake pads
	2. Pad wear excessive or one-sided	Replace brake pads
	3. Brake disc not flush with floating caliper	Clean guide screws, do not grease Clean contact face between wheel hub and brake disc
	4. Contact pattern of pads and brake discs	Visually inspect brake discs and pads If necessary, precision-turn brake discs If necessary, replace brake discs and pads
	5. Rust edges on brake discs	Precision-turn brake discs or replace
	6. Pad loose	Replace brake pads
	7. Wrong type of pads	Replace brake pads
Rattling, humming, steering wheel torsional vibrations during brake operation	1. Fouling of contact surface between brake disc and wheel hub	Clean contact surface between brake disc and wheel hub
	2. Excessive thickness deviation within braking surface	Measure brake disc thickness Precision-turn brake discs or replace
	3. Contact pattern of pads and brake discs	Visually inspect discs and pads If necessary, precision-turn brake discs If necessary, replace brake discs and pads
	4. Brake disc runout	Precision-turn brake discs , replace if necessary
	5. Excessive wheel bearing play	Replace wheel bearing