FAQs— Mercedes Benz Brake Disc
- The brakes of my Mercedes Benz squeal when I stop fairly short. Has the brake disc something to do with it?
That high-pitched squealing sound is due to vibration, and yes, it can be a sign of a disc that necessitates machining. However, that noise may also be an indication of other brake problems like worn-out brake linings or loose brake pads. It’s also possible that the pads have lost their anti-rattle clips. Or, the hardware used to attach the brake calipers may be worn. That squealing sound can also be heard when substandard brake linings are installed. So before you think of a brake disc replacement, you’d better do some troubleshooting first.
- How about that grinding noise that I noticed as I stepped on the pedal? Is that an indication that I need to get a new Mercedes Benz brake disc soon?
This problem isn’t caused by the brake disc, but it can directly affect the discs or drums when neglected. If you experienced such, you should pull over immediately and ask someone to tow your ride to a brake or auto repair shop or to your garage if you want to do the task by yourself. Driving your Benz further would do you no good but would rather damage the brake discs or drums. That grinding noise is caused by brake linings that have worn down excessively, causing the metal part of the brake pad or brake shoe to contact the brake disc. That metal-to-metal contact can quickly damage the most expensive mechanical components of your brake system.
- During inspection, I noticed cracks on my Mercedes Benz brake disc. What could be causing these?
Those cracks on the braking surface develop due to too much heat that’s caused by torque imbalance. Such imbalance transfers a bigger part of braking function to one or a few of the vehicle’s brakes. The brakes that perform much of the braking action will experience premature disc wear and will sometimes develop radial cracks.
- What about those black spots on the disc? Are those serious signs of brake problem? How can that be fixed or avoided?
A brake disc with such spots is called maternsite spotted disc, and those spots are indications that the disc has been subjected to extremely high temperatures, which can be caused by a brake system that’s improperly balanced, a dragging brake, or constant hard braking and severe application of the brakes. Continued exposure to extremely high temperatures will bring structural changes on the disc material, making it more susceptible to cracking. Fixing this problem involves disc resurfacing to bring back its concentricity by shaving off or removing the hard raised spots. But, if resurfacing causes the thickness of the disc to be below the recommended limit, then you have no choice but to replace it. The entire brake system should also be inspected for proper balance.
- One of the brake discs in my Mercedes Benz is slowly turning bluish. Is that normal?
No, that isn’t normal. A “blueing“ brake disc means that it has been exposed to extremely high temperatures, which can be caused by frequent hard stops or any imbalance in the brake system. This condition does not necessitate brake disc replacement or resurfacing as long as the disc thickness remains within the recommended tolerance. One way to correct this brake issue is to check the brake system of your Mercedes Benz for proper balance. It’s also advised that you check the thickness of the disc as well as the clearance and adjustment of the caliper. If you continue to ignore the blueing disc, it may result in a martensite condition or disc cracking.
- After installing a new Mercedes Benz brake disc, how will I know if I’ve done the installation properly?
Of course, the best way for you to know if you’ve properly installed your new brake disc is to do a test drive. However, you may also perform a “mini” test drive first. You can do this by lowering your car and placing wheel blocks a little behind as well as in front of the front and rear tires. The blocks must not be too close to the tires so they can freely do short movements like rolling back and forth while you’re testing the brakes. On the actual test drive, see to it that the vehicle doesn't pull and that the brakes are working well and don’t make clunking noises.
- Why do I still need to clean my newly purchased brake disc before installing it on my Mercedes vehicle? Isn’t it clean enough for automotive use?
It is necessary because new rotors usually have a layer of oil, which is applied to prevent rust while they're being stored on the shelf. You can get rid of this oil using brake cleaner or carb/fuel-injector cleaner.
Tips on How to Keep a Mercedes Benz Brake Disc in Top Condition
Brake discs or rotors work through a simple process. The caliper or clamp-like object around the brake rotor use the brake pads contained within it to apply stopping pressure to the rotor, therefore slowing down the car when the brake pedal is pushed down. Because the rubber tires won't move unless the wheel turns, the traction from the halted tires will stop the car on its tracks, the rubber acting like rubber stoppers you see on chair and table legs or door stops. With that said, the rotor and pads tend to experience wear and tear from daily use, requiring preventive maintenance on the motorist's part to mitigate damage and eventual breakdown.
- Take note of the first signs of wear and tear
The first signs of brake wear and tear include clicking noises, a screeching sound when braking, a pulsating pedal, excessive vibration, the brake disc or rotor looking warped or corroded, and the brake pads appearing a bit too thin or worn out (like a well-used eraser). To prevent these symptoms from occurring, you should do periodic rebuffing or outright replacement of these parts. Thankfully, maintenance and inspection of these items are relatively easy tasks compared to the maintenance of the more sensitive components of your Mercedes Benz.
- Regularly refill your brake fluid.
Brake fluid should be changed in accordance to your Mercedes Benz's user manual or manufacturer recommendations. Typically, it should be changed every couple of years. This is because old contaminated brake fluid tends to attract moisture because it's hydroscopic. Moisture-filled brake fluid reduces the boiling point, making it easier to boil under heavy heated braking. Boiling brake fluid can make your brake assembly fade when driving down mountainous roads while hauling heavy loads. The moisture itself can corrode the metal components of your brake disc, which can also compromise this component.
- Inspect your brake discs visually.
Before inspection beings, make sure your car hasn't been driven for a couple of hours or at least an hour, since the caliper tends to heat up due to friction when you're driving. Hoist the vehicle up on jack stands. Remove the wheel and give the disc a visual inspection. Check the thickness and integrity of the rotor, caliper, and pads. If the disc shows symptoms of uneven wear or damage, you'll need to seek professional mechanic help to get it either reground or altogether replaced. To avoid faded brake discs, don't overuse your brakes. Brake gradually to slow the vehicle down instead of flooring your brakes every time.
- Check out the condition of your brake pads.
To see if the brake pads have been worn down to nothingness or not, you should remove the caliper from your brake rotor by disengaging its mounting bolts with a six-point wrench. Get the caliper out of the car and away from the disc through a bungee cord or a strong wire. Don't allow it to be hung by the brake hose. The pads are found within the caliper. They're secured by either clips or bolts, depending on the model and year of Mercedes Benz you're driving. Check them for signs of damage and see how much of them are still left. You can also keep your brake system happy by getting uprated brake pads or bigger brake disc replacements.