Do the rotors needs to be replaced with the brake pads?

I have a brake pad wear light that is illuminated on my dash. I called a mechanic who said you cannot replace the brake pads only on a Mercedes and that I also need to also replace the rotors. Is this true?

My car has 128000 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
All Mercedes manuals recommend replacing the brake pads and rotors in sets. The rotors cannot be resurfaced due to material used in the rotors. The rotors are made of softer materials than most vehicles and wear more and should be replaced as a set.

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Deep grooves that have developed in a worn rotor will act as a hole-puncher or shredder and damage the pad material as it is pressed against the rotor. Be sure to replace the rotors when changing the brake pads.
As a general rule, you should get your brake pads replaced every 10,000 to 20,000 miles to keep wear to a minimum. When it comes to your rotors, you have a bit longer. Your rotors should be replaced between 50,000 and 70,000 miles to keep your brakes in peak health.
You do not need to replace all 4 rotors at the same time, but it is recommended to replace the rotors and pads as a set for each axle front or back at the same time. If the front brakes need to be replaced but the rear brakes are not worn out yet, then you do not need to replace the rear brakes.
Often, Mercedes-Benz rotors need to be replaced every 30,000 – 80,000 miles depending on the factors above. It is always best to reference your Mercedes-Benz maintenance manual for more information.
However, they typically last between 25,000 and 65,000 miles.
If you don`t replace the rotors when needed, you risk brake failure and an accident. The rotor absorbs and dissipates heat when the brakes are applied. The thinner the rotor becomes, the more heat is absorbed. This excess heat warps the rotor.
If your rotors are faulty, they may produce a squeaking, squealing, or grinding sound when you apply the brakes. Warped rotors usually emit a high-pitched squeak, while severely worn rotors tend to make a scraping noise.
Rotors cost between $30 and $75 each. Higher-quality rotors like Duralast Gold, which feature a coated hat and edge and are designed to outperform your vehicle`s original equipment, usually cost a little more. Labor at a shop to replace rotors and pads is approximately $150 to $200 per axle.
Common Causes of Worn Rotors

Panic or emergency braking at high speeds can cause rotor wear. The friction from the brake pad grabbing the rotor can cause high enough heat to result in wear.

Many factors determine how long your rotors will last, but you can generally expect them to require replacing somewhere between 30,000 and 70,000 miles of driving. For an average driver covering 12,000 miles per year, this means that brake rotors may need replacing anytime between 2 1/2 years and six years of driving.
If your rotors are faulty, they may produce a squeaking, squealing, or grinding sound when you apply the brakes. Warped rotors usually emit a high-pitched squeak, while severely worn rotors tend to make a scraping noise.
If your rotors are faulty, they may produce a squeaking, squealing, or grinding sound when you apply the brakes. Warped rotors usually emit a high-pitched squeak, while severely worn rotors tend to make a scraping noise.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Brake calipers needing replacement after brake pads and rotors were replaced?
ANSWER : I think you have it backwards. The pads and rotors do not cause bad calipers, but a sticking or binding caliper can cause the pads to wear excessively and cause the pads to dig into the rotors. The calipers may not of been binding until the caliper pistons had to be pushed back to install the new pads. It would be recommended to have the brake system flushed after replacing the calipers, pads, and rotors so the system has all new fluid. A certified technician from YourMechanic can come to your car’s location to perform any needed repairs with your brake system.

Does my car need new brake pads and rotors?
ANSWER : Hi there:

In most instances, if the brake pads have not fully worn out, the rotors will not suffer scarring or pitting which typically means the rotors need to be surfaced or replaced. However, it really depends on the damage that has been done or if the rotors may have been warped due to excessive heat or braking. Before you take your vehicle to any of these shops, you might want to have professional mobile mechanics complete a brake pads and rotor inspection to give you an accurate assessment of the repairs you need to have completed on your Volvo.

how thin can rotors be before replacing?
ANSWER : Nothing sounds right about that. There are references that tell mechanics how thick rotors are when new, when they’re too thin to machine, and when to discard. The rotors need measured with a micrometer to check this. Rust and some other factors can shorten the life of a rotor before it’s too thin, but you should have been informed of this. They are many reasons to replace a caliper. Brake pads being too thick are not one of them. Either the piston in the caliper is not compressing all the way, there’s a seized caliper slide, or they have the wrong pads. If the piston is stuck, this warrants replacement. I would get a second opinion from a certified mechanic, such as one from YourMechanic, who can diagnose your brake system and suggest what to do from there. Good luck.

I need to speak with Ricardo which was the mechanic on my car in March before booking next appointment. Subject Rear Brake Rotors
ANSWER : Hi Doug. I have forwarded your inquiry to our customer sales department to see if they can see if they are able to put you in contact with Ricardo. If you had work previously done, you should have been sent a direct email from our sales team. You might want to reply to that email directly to expedite the contact process, as this forum is reserved for automotive maintenance recommendations and repair suggestions. Thanks.

My car brake pedal vibrates while braking….so do i need to get front rotors replaced or rear rotors replaced? What are charges?
ANSWER : A pulsating brake pedal can be caused by front, rear, or all 4 rotors being warped or out of round. Typically when it’s the front rotors, you will feel the vibration in the brake pedal and the steering wheel. When the rear rotors are warped, you may feel it in the brake pedal and more in the seat, feeling it in your back side. Whether front, rear, or all 4, if the rotors are replaced, it’s a good idea to replace the pads as well.
The best approach would be to have a certified technician inspect the brakes to determine where the pulsation is coming from. An accurate estimate for repairs can be given at that time.

Rear brake job
ANSWER : Hello, thank you for writing in. These situations are understandably questionable. The service providers at a lot of common oil changing and tire repair centers will quote you for a variety of things that can be updated. This does not always mean you are in dire need for more repairs. If braking seems to be harder, spongy, or takes longer, then you have reason to be concerned. Otherwise, you should check the amount of brake pad material left on the calipers. This can be visually inspected without too much trouble. Remove the wheel and physically measure the amount left, compare them to your vehicle specifications. It is a little early to worry about brake fluid or the rotors. However if the brake fluid is low, the rotors are warped from a hard stop, or there are obvious issues you should look into the system further. Only further inspection will confirm or deny the recommendations. For a second inspection, contact our service department to schedule an appointment.

Uneven brake rotor wear
ANSWER : Hello. I tried to view the pictures but the link seems to be broken. It sounds like you have two different problems reading the description of the problem. The first is the brake pads being too tight and binding in the caliper bracket. This is most likely caused from the pad ends are not machined smooth and do not slide into the caliper bracket smooth. This will cause them to bind and cause low brake application or will keep the brakes partly applied wearing them down quickly. The other possible problem is the caliper may be binding on the slides or the piston is binding. If you would like precise advise on exactly what needs repair, have a certified professional diagnose the brake system in person and follow through with correct repairs.

Why do I constantly need to replace the brake rotors and brake pads?
ANSWER : Hi there. That’s a really good question. What reason were you given that the rotors need replacing? What symptoms are you experiencing? If you have a brake vibration, the rotors should have enough thickness after a year, unless you drive 80k miles a year, to be resurfaced to correct the vibration. What is the quality of the parts being used? There are a lot of unknowns here that a qualified technician could answer.

Rotor measurements should be provided and the minimum specification should also be known to be sure the rotors can be resurfaced. YourMechanic has several available technicians that can assist you with a brake safety inspection and can advise you on proper repairs for your brake system.