Brake discs A.B.S. BMW 8 Series

If you feel wobble and vibrations when braking and hear a sharp screeching sound, then, probably, the time for replacement has come. To make sure that the problem is caused by these components, inspect them for damages: they shouldn’t have any cracks, chips or be warped. Measure the residual thickness of the parts.

Usually, manufacturers cut a wear indicator groove on the disc surface, which helps to monitor the wear. Replace the parts if these marks have become invisible. Also, the minimum thickness can be marked on the disc edge. Measure this value with a caliper gauge and compare it with that specified by the car manufacturer.

The allowable wear depends on the brand and type of the parts. This value may vary for conventional (solid), vented, drilled, waved, and slotted parts. As a rule, it should be within the 1.5–3.0 mm range.

For this job you will need:

1. A lifting device.
2. A set of open-end and ring spanners.
3. A flat and Phillips screwdrivers.
4. New brake pads, as they should be replaced together with the discs.

A detailed procedure is listed in your car’s workshop manual. The general steps are as follows:

• Apply the parking brake.
• Loosen the wheel bolts.
• Lift the car.
• Unscrew the wheel bolts and remove the wheel.
• Press in the brake caliper pistons.
• Remove the fasteners connecting the brake caliper to the steering knuckle and remove the caliper. Avoid twisting the brake hose and putting excessive load on it.
• Unscrew the fasteners.
• Remove the old part from the wheel hub.
• Apply protective grease on the new one, remove excess of the product, using a cloth.
• Install the component, fasten it with locking screws and assemble all the other components in the reversed order.

After completing the installation, bleed your brake system.

As the front axle of a car is exposed to higher loads when braking, the front brake discs wear out faster and need to be replaced more frequently. That is why there is no need to replace all 4 parts at once. We recommend installing the components in pairs, with replacing the brake pads at the same time, regardless of how worn they are. During the first 150–200 kilometers when the components are bedding in, it is important to avoid continuous or abrupt braking.

When buying new spare parts consider your car’s operating conditions and your individual driving style. The components are divided into three price categories:

• Budget. It includes the products from Ridex, Japanparts, Febi, and some other brands. These parts are optimal for relaxed city driving. They are inexpensive.
• Mid-price. The products from A.B.S., Ferodo, Metzger, VAICO, Delphi Technologies, and other companies belong to this category. They combine good quality with a reasonable price and are suitable for dynamic city and highway driving.
• Premium. These are the products from Brembo, Zimmermann, Hella, Bosch, Textar, and TRW. The discs are made from high-strength materials, using cutting-edge technologies, and can withstand extreme loads. However, these parts are expensive.

In urban traffic conditions, drilled and slotted parts should be used if:

• You prefer aggressive driving style. Abrupt acceleration and braking cause overheating of the assembly and make it necessary to efficiently remove brake pad wear products. Slotted and drilled parts are the best solution in this case.
• You own a heavy SUV or a pickup. Due to the high vehicle weight, the parts overheat and break down faster. Drilled components carry heat away more efficiently, so they are preferable for this kind of car.
• If you want to add a sportier look to your vehicle. These parts are well visible through alloy wheel rims and add a unique style to your car.