Noticed a bit of smoke and a burning smell from your brakes?
The brakes use friction to slow your wheels, and friction generates heat — but it should never be enough to torch them!
So why is there a burning smell from brakes?
And the more immediate concern — what should you do about it?
In this article, we’ll unravel the most common reasons behind that burning rubber smell and what you can do if it happens. We’ll also look at some other sources of a burning smell.
This Article Contains
- 7 Reasons For A Burning Smell From Brakes
- 3 Things To Do About A Burning Smell From Brakes
- 2 Burning Smell FAQs
Let’s dive in.
7 Reasons For A Burning Smell From Brakes
A burning smell from your brakes isn’t always critical, though more often than not, it means something is wrong.
Let’s look at the various reasons your brakes could be emitting a burning smell:
1. New Brake Pads
Have you recently had a brake pad replacement?
New brake pads are coated in resin and can produce a burnt rubber smell when initially used.
It’s from the resin curing as each brake pad settles into your rotor.
The heated rubber smell means the brake pad material is getting stronger, so there’s no cause for concern unless your new brakes aren’t performing, or if the smell goes on for more than a few days.
2. The Emergency Brake Is On
This is probably the most common reason for a burning rubber smell from your rear brakes.
Why the rear brakes specifically?
Because that’s where your emergency brake (also called the parking brake or hand brake) mechanism is usually located.
Did you leave yours on?
Your car might have felt sluggish, and if you’d driven a fair amount of distance, an engaged parking brake could cause overheated brakes — that’s where the burnt rubber odor comes from. There might have been some squealing or grinding sounds too.
The best way to avoid this is to make it a conscious effort to release the parking brake once you’ve shifted into gear. Glance at your dashboard to make sure the parking brake light is off before you press the accelerator. It’ll become a habit in no time!
3. Overworked Brakes
Overused brakes or aggressive braking is another cause of overheated brakes.
If you drive in mountainous terrain, that hot brake smell can turn up as you’re riding the brakes going downhill. A similar thing happens when there’s a lot of hard braking, even in regular traffic.
Leaving the brakes on for minutes will allow the heat from continuous friction to build up, creating that scorched rubber smell.
If this keeps up, your brakes might begin to feel spongy as brake fluid starts to boil, and there could be smoke from burning brakes. Brake fade could start to settle in, where your brakes are so heat soaked that braking performance is significantly reduced.
4. Worn Out Brake Parts
The brake pads and brake rotor dissipate heat through their material.
As these brake parts wear down, their ability to dissipate heat diminishes, possibly generating that burning plastic smell because they heat up faster. This excess heat can, in turn, heat up the brake fluid.
What does this mean?
The boiling point for brake fluid drops as it ages, reducing its resistance to heat. When there’s excess heat, some of the aged brake fluid turns from an incompressible fluid into compressible gas.
As a result, there’s reduced hydraulic pressure from the brake pedal. You’d have to press the brake pedal more to get the caliper to squeeze the brake pads, increasing the wear on already-old brake parts.
5. Seized Brake Caliper
With a seized brake caliper (or stuck caliper), the caliper cannot release the clamping force on the brake rotor. This can happen if a caliper piston is jammed, keeping the brake pads in contact with the rotor — creating constant friction and heat.
If you have a stuck caliper, you’ll likely notice a drag in the wheel, a hot brake smell, or even smoke. You might also have to use the brake cleaner more often for a particular wheel because a stuck caliper will generate excessive brake dust.
6. Stuck Wheel Cylinder
If your car uses a drum brake system on the rear brakes, then a stuck wheel cylinder could be causing the burning rubber smell.
Just like a caliper piston in disc brakes, the wheel cylinder can get jammed too, keeping brake shoes pressed against the brake drum.
The continuous friction keeps the heat on and can worsen in a drum brake because it dissipates heat less efficiently than disc brakes.
7. Pinched Brake Hose
The steel brake line carries brake fluid from the master cylinder to the braking mechanism at the wheel. A rubber brake hose substitutes the brake line where joints move.
If a brake hose is pinched, it may allow brake fluid pressure to enter the brake caliper but prevent it from leaving. The continuous pressure would keep the brake pad against the rotor, displaying similar symptoms to a stuck caliper.
We’ve now seen some of the more common reasons for a burning smell from brakes.
But what can you do about it if it happens?
3 Things To Do About A Burning Smell From Brakes
Here’s what you should do when you smell that odd burning car smell:
1. Stop And Let It Cool
Your car generates a lot of heat from different parts, so your best course of action is to pull over and determine the problem.
If you suspect your brakes are burning, stop and let them cool down. Overheated brakes encourage brake fade, which could be especially dangerous if you’re driving in a hilly region.
And if you can’t figure out what’s causing the burning smell, call a mobile mechanic for help.
2. Try Engine Braking
Use engine braking the next time you head down a long slope.
Downshift your gears instead of riding the brakes.
While engine braking is most suited to manual transmission vehicles, it’s not impossible with automatic cars.
If your automatic car has paddle-shifters or a console-mounted gear lever, then you can use these for downshifting. Even a regular automatic engine (without alternate gear options like paddle-shifters) has a low gear that can be used for this purpose.
However, don’t do this for regular braking and definitely not at high speeds.
3. Reach Out To A Professional
Frequently burning brakes usually necessitate a brake check and possibly a brake replacement.
The burning rubber smell could stem from a host of reasons, so it’s better to get the entire problem resolved. For this, you’ll want a reliable, thorough mechanic to review your brake issue.
Luckily, there’s AutoNation Mobile Service.
AutoNation Mobile Service is an accessible, convenient mobile auto maintenance and repair solution.
Here’s what they offer:
- Brake repairs and replacements can be done right in your driveway
- Expert, ASE-certified technicians execute vehicle inspection and servicing
- Online booking is convenient and easy
- Competitive, upfront pricing
- All maintenance and repairs are completed with high-quality equipment and replacement parts
- AutoNation Mobile Service offers a 12-month | 12,000-mile warranty for all repairs
For a quick and accurate cost estimate of brake repairs, fill this online form.
Now that you know how your brakes can burn and what to do about them, let’s look at a couple of related FAQs.
2 Burning Smell FAQs
Here are answers to some other burning questions that you may want to ask.
1. What Else Causes A Burning Smell From My Car?
While overheated brakes could undoubtedly cause a burning smell, there are several other possible suspects:
A. Car Smells From The Clutch
An overheated clutch can smell like burning rubber, almost like burning brakes.
It can happen with excessive clutch slippage.
Sometimes this is when the clutch pedal isn’t fully depressed during gear shifts or when the clutch is intentionally slipped while climbing a steep slope. Clutch slipping can also occur if it’s worn and needs replacing.
B. Electrical Issues
Electrical problems like a blown fuse or a short circuit can emit burning smells. These can cause melted insulation around the wiring or the fuse, which will also produce burnt odors.
C. Broken Heater Core
The heater core is a small radiator that uses the hot engine coolant to warm the vehicle cabin.
If the heater core leaks coolant, it can produce a burning smell, the windows can fog up, and even the engine can overheat. There could be debris stuck in the heater vent as well, causing the burning smell.
D. Oil Leak
You could detect a burning oil smell if your vehicle has an engine oil leak that drops on a hot exhaust.
The scent might not be noticeable in the cabin, but it’ll be very obvious outside, and there might be some fumes from the burning oil too.
E. Foreign Object In The Exhaust
A foreign object (like a plastic bag) stuck to your exhaust could cause a burning smell.
The exhaust system has some very hot components, so it’s a good place to make a quick check if a charred scent turns up.
F. Worn Drive Belt
The drive belt (also called the serpentine belt) can melt from extremely hot engine components or a seized pulley. If a pulley is seized, the excessive friction resulting from this creates a lot of heat and squealing noises.
G. Clogged Catalytic Converter
The catalytic converter converts toxic exhaust gases into less harmful emissions.
It operates at temperatures in excess of 800oF (427oC), so you can imagine how much hotter it can get if it’s clogged. A clogged catalytic converter has the potential to start a fire, and it’ll glow if it’s too hot.
2. What Other Signs Indicate A Brake Problem?
Burning brake smells are usually a sign that your brakes may need some attention.
However, it isn’t the only sign that can signal a brake system problem.
Here are some other common ones:
- Dashboard brake light glows: a lit brake light can mean your parking brake is on or your brake pads need a change.
- Squealing or grinding sounds: there are several causes for this, ranging from overworn brake pads to a misaligned or warped rotor.
- Brake pedal issues: if you have to press the brake pedal more to engage the brakes, or if the brake pedal suddenly feels very hard, you have brake issues.
- Brake fluid leak: a puddle of amber fluid under your car or near a wheel could mean a leak in a brake system component.
If you can’t determine the root cause of these, get hold of a mechanic to help you out.
Closing Thoughts
Frequently overheated brakes will become less effective over time and start to smell.
To keep your brakes in peak condition, follow some of the tips we mentioned above, and you should be fine.
However, if your brakes do overheat and you need help resolving the problem, don’t hesitate to contact AutoNation Mobile Service. Our expert mechanics will drop by to lend you a hand in no time!