So you’re driving to the office, and you suddenly smell smoke. Alarmed, you wonder what it could be—until you see smoke coming from the back of your car.
Now, it doesn’t take a mechanic to know that when your car starts emitting smoke, you have a problem that requires immediate attention. Smoke is often a sign that something is wrong with your brake system. It is usually a result of excessive heat, which may be caused by too much friction.
The vehicle’s brake system has several components that need friction to function, such as brake pads, rotors, and calipers. However, excessive friction (and a number of other reasons) can cause your brakes to produce smoke.
Smoking Brakes: What’s Causing It?
This can be a frightening scenario, especially for new drivers. Seeing smoke or smelling something burnt when stepping on the brakes is certainly not a good sign—but why is it happening?
If you’re wondering why your brakes are producing smoke whenever you’re driving, here are the most common causes:
Although smoking brakes may be a sign of a serious problem in your braking system, it may also be caused by overheated brake components due to excessive braking.
For example, driving downhill may cause excessive heat to build up, leading to a burnt smell or, in worse cases, actual smoke coming out of the front or back of your vehicle.
Aside from going downhill, take note that braking suddenly while driving at high speeds or accelerating while pressing your brakes at the same time may also cause the same symptom.
When this happens, experts advise that you shift to a lower gear to limit your speed instead of riding your brakes, in order to cool them down. If you must come to a stop, park the car and take your foot off the brake pedal to avoid creating hotspots on your rotors, which can lead to warping.
New Brake Pads and Rotors
Most of the time, new brake pads and rotors will produce a burnt smell rather than actual smoke. This scenario may be normal, especially when you don’t notice anything wrong with your vehicle’s brakes.
Manufacturers are expected to condition these parts for use, but they may still need to undergo a break-in period once you finish the installation. This may be referred to as part of its post-installation curing and, unfortunately, emitting smoke or a burnt smell is part of the process.
Technically, there is nothing to worry about if you notice your new brake pads and rotors smoking, especially when it happens after frequent or hard braking. But while this can be normal, make sure to observe your brakes over the next few days. If there isn’t an underlying issue with your brake system, the smoke and/or burning smell should go away on its own.
However, if in doubt, the best course of action is to take your vehicle to a mechanic.
Stuck Caliper or Wheel Cylinder
Generally, anything that causes your brake to remain applied will cause overheating. One of the common reasons why your brakes overheat is a malfunctioning or stuck caliper.
Anything that hinders your caliper pistons from retracting or sliding back into their released position may cause too much friction, which will then cause a burning smell or smoke to emit from your brakes.
In a similar instance, a stuck wheel cylinder may also be the culprit.
If you notice that your vehicle pulls to one side when braking, or any other brake related symptom, there is a great chance that something is wrong with your brake system.
Needless to say, anything wrong with the brake system is a safety risk for you and your passengers.
Restricted Brake Hose
Aside from stuck brake components, another thing that could cause your brakes to remain applied is a restricted brake hose.
Just like any other car part, this rubber hose can wear out over time. This may cause blocked brake fluid flow.
How does this scenario cause the brakes to remain applied? Blockage in your brake hose may cause your hose to act as a 1-way valve. For example, brake fluid may successfully travel to the caliper from the master cylinder. However, a flap or blockage in the hose may block the brake fluid from coming back, causing the brakes to be constantly applied.
This may then lead to overheating and smoking brakes.
Malfunctioning Brake Master Cylinder
Lastly, your brake master cylinder may be to blame. Anything that does not allow brake fluid to travel may cause your brakes to smoke.
If your brake master cylinder is faulty or if you think that it is due for a replacement, have it checked or replaced by a trusted mechanic.
How to Fix Smoking Brakes
Now that you are aware of the reasons why your vehicle’s brakes are producing smoke, let’s move on to how you can fix the problem.
The best thing you can do at this point is to bring your vehicle to the service center for proper diagnosis. Your mechanic should be able to pinpoint the problem and fix the issue for you.
Replacing brake components may be necessary, depending on the cause of the problem. To prevent corrosion, it is also advisable to take any brake work as an opportunity to lubricate any moving part with high-temperature grease.