How to Repair a BMW Brake Disc
Like the brakes of your bicycle, your brake disc or rotor makes use of a caliper that squeezes the brake pads against the axle of your wheel, which slows their movement down. Meanwhile, the unmoving tires and their rubber traction on the road will do the rest in stopping your ride. With that said, here's what you need to do in case your brake disc is busted, warped, or significantly compromised:
Difficulty Level: Moderate
What You'll Need
- Brake spray
- Various wrenches
- Heavy rubber mallet
- Turkey baster or siphon
- Jack stands and tire chocks
- Large C-clamp to depress the caliper
- Wheel removal tools such as jack and lug wrench
- Rust buster spray if rotor is rusted to wheel axle plate
Step 1:Put your car on jack stands to hoist it up then remove the wheel. Put wheel chocks on the other wheels to keep the car from rolling. Once you gain access to the disc, check it for signs of damage to see if it needs replacement. If the rotor is thinning out or has track marks on it, that indicates the need to replace it post-haste. If the disc is smooth and level to the outside rim edges, it's fine and it's probably the brake pads that need replacement.
Step 2: Draw the brake fluid out using a siphon of some sort (or a turkey baster) from the master cylinder. Leave the cap off and remove a third of the fluid. Put it in a clean container for possible reuse.
Step 3:Compress the caliper with the C-clamp by placing one side of the clamp onto the caliper's interior side and the other end on the exterior side. Tighten the clamp by hand to depress the caliper. Keep an eye on the level in the master cylinder to avoid overflow.
Step 4:Remove the caliper by unbolting its bolts. Replace the pads along with the rotor itself to ensure smooth uncompromised braking every time. Pad removal should be done carefully if you wish to reuse or recycle them.
Step 5:If you can't set the caliper out of your way in a stable position, hang it somewhere with wire without twisting or disturbing the brake fluid line. Don't depend on the fluid line to hold the caliper up because it could get damaged itself.
Step 6:Pull the disc towards you. If it doesn't slide off smoothly, it might have some rusty edges. You might have to spray it with rust buster, tap the edges of the brake disc with a mallet, or twist hard then pull the rotor back until it comes loose.
Step 7:Slip your new rotor into place to replace your compromised stock rotor. Make sure it's placed against the axle plate and seated all the way back. Place the pads and discs within the caliper properly. Tighten the bolts of the caliper.
Step 8:Use brake spray to clean the brake disc and any leftover rust and debris from the previous rotor. Don't wipe the fluid off. Let it evaporate on its own. Make sure the rotor's surface is free of oil too.
Step 9:Put the wheel back on and do the same steps in removal and replacement of the other rotor on the same axle. Fill the master cylinder with brake fluid (whether a new fluid or the fluid you siphoned earlier).
Brembo Brake Disc
Designed to provide your car with the right amount of stopping power, the Brembo brake disc is made of special cast iron with increased carbon content to provide just the right amount of friction that your vehicle needs to stop. The high carbon also pulls double duty to reduce unwanted noise and vibrations--keeping things quiet even in the toughest binds. With Easy Check, a driver can readily check for wear and tear with a glance--two holes drilled onto the surface vanish after repeated use. Add to that Brembo's patented pillar venting technology (PVT)--on vented rotors only--which are designed with longevity in mind. PVT improves cooling capacity, and significantly increases resistance to heat cracking by up to 40%. As with all other products in their line, Brembo's brake disc is certified by TUV (the prestigious German technical testing association) for compliance with all necessary global compliance standards. This disc also comes with a comprehensive 2-year or 12,000 mile warranty.
Zimmerman Brake Disc
The Zimmerman Coated Brake Disc is carefully crafted and designed to be both OE-equivalent in quality and direct-fit in installation. High carbon content in this product makes it both more silent in operation and less prone to damaging heat build-up. It is coated with proprietary Zimmermann coating to stop the formation of rust at the vulnerable hub, and to add a little visual flair as well--no need to remove coating before mounting. The body of the disc itself is hewn out of high tensile strength gray cast iron for improved durability of the actual disc itself. Carefully machined and balanced, the Zimmermann brake disc is guaranteed to perform up to expected braking standards for a long time. As with all German products, this brake disc meets and passes all necessary quality assurance standards including ISO 9001 and TUV certifications. Additionally, all Zimmermann brake discs come with a limited one-year or 12,000-mile warranty.
Balo Brake Disc
Balo brake discs are designed to meet the exacting standards of luxury brands like Mercedes Benz and BMW. Made from high-tensile, high-quality cast iron, these brakes are designed to be durable and long lasting. Undergoing meticulous machining via a Blanchard grinder, these brakes have a leveled, parallel surface that is far less prone to warping than other brake pads made the traditional way. Balo brake discs also incorporate more carbon in their construction to make them more resistant to thermal cracking and scoring when put under the extreme pressures of driving. This carbon also increases the friction coefficient up to 40%, giving you superior stopping power in every situation. With all the industry-required certifications from ISO 9001 and TUV, plus a hefty limited 1 year or 12,000 mile warranty, Balo brake discs are sure to serve their function for a very long time.