What?
We're often asked by our customers about the condition of brakes. The questions range from iDrive error messages to irregular brake sound to general brake maintenance questions. This is no surprise as brakes is one of the most important component within a car. A brake malfunction can be catastrophic!
When?
Let's start with 'when'. In a modern car like a BMW, the iDrive system will inform the owner if there are any problems with the braking systems or advice when should the owner expect to change the brakes.
However, the owner should not rely completely on the iDrive system and get your local mechanic to check the condition of your brakes visually during service. This is especially important if you change your brakes outside an authorised dealer or a workshop specializing in BMW as they may not have the necessary tools and knowledge to properly install and reset the system.
As a general rule, a brand new set of brake pads should last between 50,000km - 70,000km in Malaysia. This of course depends on the driving style as well.
It is also possible for the brakes to be worn out unevenly. This requires visual inspection to properly check the condition of the brakes. For example, the image below shows the unevenly worn pads.
Car owners should also take note of the brake discs (also called rotors) can last up to 2 brake pad changes. When a disc is badly scratched or 'burned', it can no longer be used and owners are advised to change their discs as soon as possible. All brake discs have a minimum thickness for it to function properly.
We're also often asked about brake fluid. The iDrive system will remind owner to change the brake fluid. When this message is shown, check the brake fluid reservoir and ensure that there are sufficient fluid and the color is almost transparent.
Why?
Why do you need to change your brake pads? When the brake pad are worn, the braking capacity will drop significantly. The brake pad's body is made of metal and it will scratch with the disc. This produces the screeching sound and the worn pad will scratch and damage the disc and causing the car to lose braking ability.
Where and Who?
While it is not necessary for owners to return to Service Centers due to the lack of brake pad warranty, it is important that customer chooses a reputable workshop that carry genuine BMW parts and are familiar with the process of changing BMW brakes.
Changing brake pad alone generally takes 15 minutes per wheel. Changing the disc will take an additional 10-15 minutes per wheel.
A workshop familiar with BMW will also reset the iDrive system so that the new brakes and sensor values are reflected in the system.
How
When changing the brake pads for a BMW, the sensor needs to be replaced as well. The brake system needs to be thoroughly cleaned using brake cleaning chemical or air to remove the brake dust. When installing a new set of brakes, the technician needs to ensure that there are no oil stain on the brake contact area. Copper paste should also be applied to maintain brake longevity and ensure there are no squeaking sound.
Once the new brake pads, discs and sensors are installed, a computer will be used to reset the iDrive brake values. Prior to handover to customer, the newly installed brake needs to be tested by a qualified technician to ensure it is in working condition for safety.
Bonus: Brake maintenance
Brake pads will generate a lot of brake dust which will stick to other brake components. Combined with a dirty wheel, this then results in screeching sound and drop in braking ability. So it is advisable to regularly clean your wheel to reduce the build on the brake dust. You can either clean it with high pressure water or air at home. There are also some brake cleaning chemicals available, but these must be used with caution due to is harmful ingredients.
By routinely cleaning your brakes, you'll enjoy a longer brake lifetime. Happy Driving!