Imagine going on a road trip you spent so much time preparing for on your prized BMW. You and your passengers are all excited, but halfway through your journey, you hear a metallic scraping sound as you put your foot on the brake pedal. Or perhaps your brake warning light suddenly pops on.
Such symptoms can make anyone worry, considering faulty brakes can contribute to crashes. Indeed, experts say malfunctioning or unchecked brakes are behind 22% of accidents in the U.S.
For the same reasons, you should never ignore the signs that you need new BMW brakes. We’ll discuss these in more detail below, so read on.
1. Brake Pad’s Lining Is Down to 3 Millimeters
New brake pads have linings that are about 10 to 12 mm thick. When these wear out to 3 mm, your brakes can become noisy. You need to get them changed before they become any thinner.
If you follow your recommended BMW maintenance schedule, you’ll know when your brake pads need replacement. This is because the technician who services it will immediately inform you. Have them change your worn brake pads before they create more problems or put you at risk of a crash.
2. Your Brake Warning Light Is On
Embedded inside BMW brake pads are wear sensors, often made of rubber wires. Their primary function is to warn drivers that they have worn brake pads requiring replacement.
For the sensors to do their job, their wires must split and break an electric circuit. This happens when worn pads expose them to friction.
When a sensor’s electric circuit breaks, it notifies the Engine Control Unit (ECU). Once the ECU “receives” this notification, it’ll turn on the brake warning light. You may also receive a brake pad sensor warning message on your infotainment display.
In that case, you should book an appointment with a certified BMW dealer or repair center ASAP. Fortunately, you can schedule this online, according to the folks at BMW of SLO. A qualified technician needs to inspect your brakes for possible repairs or replacement.
3. Excessive Vibrations or Shaking When Braking
Inside your BMW wheels are metal discs known as brake rotors. Your car’s brake pads clamp onto these discs when you step on the pedal. This is what causes your wheels to stop spinning.
Over time, the rotors thin out, their surfaces can become uneven, and they can form rust. All these can impact how the brake pads interact with or touch them. For example, they can make the car shake or the steering wheel vibrate excessively.
Have a BMW-certified technician inspect your brake system before your rotors get damaged. Damaged rotors pose safety risks; they can lead to a loss of braking power or increased stopping distances.
4. Screeching or Squealing Sounds
Brake pads have a metal base covered with friction material. Every time you engage the BMW brake system, the pads thin out bit by bit. So, the more often you drive and forcefully brake, the faster the pads will wear out.
Unless replaced promptly, the pads’ metal base will become exposed. When this happens, engaging the brakes will cause the rotor to touch the exposed metal parts. This metal-to-metal interaction causes screeching or squealing sounds.
So, as soon as you hear those noises, get your brake system checked by a BMW-certified technician.
Better yet, don’t wait for that to happen; instead, follow your ride’s recommended maintenance schedule. This includes timely brake pad replacement after 30,000 to 70,000 miles, depending on your driving habits. A qualified BMW technician will let you know if they’re still good or if you need new ones.
5. Burnt Smells When Braking
Aside from screeching or squealing noises, metal-to-metal interaction can produce burnt smells. So, when you have severely worn brake pads, you may notice these odors whenever you step on the pedal. It signals that your pads’ friction material has become too thin or has disappeared.
Take your BMW in for servicing before your entire brake system suffers or fails.
6. The Brake Pedal Feels Soft or Spongy
A BMW brake pedal that’s in good condition must be firm and offer some resistance when you step on it. So, if yours feels soft or spongy, it may indicate a problem with the brake line. Air intrusion or leaks may cause this issue.
Air in a brake line can interrupt the flow of brake fluid and make the pedal feel soft. It can also reduce the pressure within the system, affecting brake performance.
As for a leaking brake line, it can result in a loss of hydraulic pressure. However, its effect is the same: a spongy-feeling pedal that can go too low, even to the floor.
7. Your Car Drifts to One Side When Braking
Your BMW’s front brake pads wear faster than the rear ones. This results from the forward momentum of your moving vehicle, which places more strain on the front brakes.
The problem is if one front brake pad wears out faster than the other. If this happens, the vehicle may veer slightly to one side when you brake.
Please note that uneven or incorrect tire pressure may also cause this symptom. For instance, underinflated tires can increase rolling resistance and make a car drift to one side. Moreover, they can make a vehicle use more fuel, causing drivers to waste money.
Either way, take your BMW to a mechanic when you experience this symptom. Otherwise, the malfunctioning brakes may place unnecessary stress on the steering rack. They may also adversely impact other vital components, such as wheel bearings or steering knuckles.
Get New BMW Brakes Before It’s Too Late
From having your brake warning lights turn on to screeching sounds and burnt odors, these are all signs that you need new BMW brakes. Please don’t ignore them, as they can cause more severe problems. Even worse, they can make your brakes fail, putting you and other road users in harm’s way.
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