It can be annoying to spend your money on new brakes only to find you’ve replaced the safety issue with another issue. A smell coming from them instead.
Do you want to know how this smell is produced? Is it dangerous, or how long it’s going to last? I will be answering all these questions in this article.
Let’s get started.
The answer to the question, why do the new brakes smell of burning, is quite simple.
Your car’s brake pads are joined together by an adhesive or resin. When brake pads are new, the resin hasn’t had the time to chemically bond together the layers within it.
Therefore, in the first few days when you use these brake pads, the frictional heat of the braking causes the resins to polymerize and form stronger bonds. This heat causes a burning smell to come from the pads. It is normal.
It’s a very good thing because this heat caused by braking makes the brake pads strong.
As mentioned, the drawback of polymerization is that it releases some by-products in the form of gases that are not very pleasant to smell, often described as a burning odor.
This process is also known as curing. In short, the polymerization of resin is the cause of the burning smell from new brakes.
Is It Dangerous?
New brake pads do smell; it is quite normal.
Remember that although most car parts don’t need to be broken in, car brakes often do. If you don’t do this, the smell can last longer, and your brakes won’t be as effective as they should be.
Every brake pad manufacturer has its own set of break in -or bedding in- instructions. The break-in method presses the pads to the rotor and generates heat, which causes the pads to polymerize.
For the first 500 miles, break-in methods can range from 10 to 20 stops at 30 mph to moderate driving with no harsh braking. It’s important to follow the break-in instructions of the brake manufacturer. . This will ensure the curing of the brake pads earlier and help you use them in the longer run.
That being said, not all brake manufacturers require this. Most brake pads in the Akebono range don’t require bedding in.
Brembo pads require bedding but aren’t prescriptive as to how to do this.
EBC Brakes give a much more thorough guide on how to break in all the brakes in their range.
New brake pads giving off a burning is not dangerous and is nothing to worry about.
How Long Will They Smell For?
The brake pads will smell for the first few hundred miles, as mentioned in the break-in procedure. In this timeframe, the curing of the resin takes place.
Once the resin is cured, the smell goes away.
Since different brake pads are made through various processes and multiple manufacturers are available, not all brakes give the same smell.
One of the manufacturers may use a molding technique that uses less resin and more heat in the molding process. These brake pads will be cured earlier than others.
Another manufacturer may use a very specific resin, which works great but has a pungent smell.
So, to recap, the odor they emit depends on the resin used, and the timeframe also varies from manufacturer to manufacturer.
What To Do If New Brakes Smell Longer Than This
One straightforward reason is that you have not followed the break-in instructions or haven’t created enough heat running through the brake pads when you’ve braked. Most bed-in instructions use the term “gentle braking” in their guidance.
This term is subjective. If pressing very lightly, you may not have generated the heat needed to polymerize the adhesive. You could try the bed-in procedure again and brake more firmly than you did before.
Other Brake Smell Causes
As mentioned earlier, the polymerization process is the main cause of smell in new brakes.
Caliper Seized
A more common reason is a stuck caliper. Do you know what a caliper does? A caliper pushes the pad against the rotor and produces friction, which slows down the wheel. The old brake pads will have been removed from the caliper to fit the new ones. It’s possible this procedure has caused damage to the caliper and caused it to seize.
This often means that the pad is in constant contact with the rotor. A stuck caliper causes the overheating of the brake pad, which results in smoke and a burning smell.
Sharp Descent
It may be that your new brake smell has coincided with a journey involving sharp declines where the brakes have been in constant use as you descend.
When you keep your foot on the brake pads for a long period, the friction accumulated during this time heats the pad, resulting in a weird smell.
Emergency Brake
The smell might be a result of an emergency brake engaged while you’re driving.
This causes a burning smell. This smell should go away once you disengage the emergency brake. If the emergency – parking brake – has remained on when you’re driving, there would normally be a sign on the dashboard to warn you, so this would be a rare cause.
What Other Smells Can New Brakes Make?
There are no other smells associated with new brakes. However, if work has been done on your brakes, brake lines leading to the caliper may have been disturbed.
In this scenario, brake fluid may escape. Brake fluid depending on its age, can give off an oily smell. If the fluid is new, this will be less intense. An easy way to check is to lift the hood and check the brake fluid reservoir level.
Generally, a burning smell from brakes is normal for the first few hundred miles. Once you have bedded in the brakes, this smell should go away.
If it doesn’t, you may not have bedded in the brakes well enough and should try again. If this doesn’t stop the smell, the brake caliper may be stuck, forcing the pad onto the rotor.
If in doubt, at this stage, get your car to a repair shop to be investigated further.
This report gives the science behind the bedding in process.
Thanks for coming to my site. In case we haven’t met yet, I’m Kevin and I just love passing on my 30 + years of experience repairing and maintaining cars.
I’ve made this site for non-technical drivers who are experiencing problems with their cars.
