“Oh No! Not Again!” You hear something noisy while braking the car. And there you go – hot spots! No matter how quality braking system we use, these spots are very common. They cause problems like vibrations, noise, brake harshness, and reduced structural integrity. So, how to get rid of hot spots on rotors?
In short, hot spots on rotors are localized areas of excessive heat buildup on the surface of brake rotors. They may appear due to uneven wear, friction, or overheating during braking (1). Again, these things can decrease fuel efficiency and increase engine emissions (2).
To prevent them, avoid using your brakes excessively or for extended periods. Your brakes should remain cool during use. Also, the brake system should have no dirt or debris (3). If you want to clean the hot spots from the rotor, use a wire brush and gently sand them. Well, there are certainly more ways –just continue reading the blog!
Hot Spots – Definition, Identification, & Causes
Definition
Indeed, these are like free WIFI spots – people gather a lot and start browsing. More precisely, hot spots are overheated rotor areas to the point where the metal begins to change its microstructure.
Another definition is the areas of excessive friction between the rotor and the brake pad or shoe. These areas cause uneven wear and tear (2, 5).
As I said, these marks cause different problems in the brake system. You may often need a new set of brakes due to those problems. Hence, if you want to get rid of hot spots on rotors, you need to identify them first.
Identification
Usually, these spots appear as bluish or discolored patches on the rotor surface. These highlighted areas indicate they have been subjected to extreme temperatures. When you get them, your rotor will warp and eventually affect the smoothness of the braking surface.
| Visual Identification | Performance Analysis |
| Discolored patches with a glazed or glossy appearance | A pulsating brake pedal when you apply the brakes |
| Signs of uneven wear or grooves on the rotor surface | Squealing or squeaking noises during braking |
| Noticeable cracks and rotor edge lip | A decrease in braking efficiency or a longer stopping distance |
What Causes Hot Spots?
While researching this topic, I found multiple reasons to get hotspots on the rotors. And you can avoid them – well, most of them. The main reasons are worn or defective rotors, varnish buildup, brake dust, and hard brake pads (2, 3). Other causes include aggressive or prolonged braking, driving in hilly terrain, towing heavy loads, and neglecting routine brake maintenance (1).
Anyway, let me describe all possible causes of hot spots on brake rotors.
| Problem | Details |
| Aggressive Braking Habits | Frequent or hard braking can increase the temperature of rotors rapidly. The chances of hot spots are also high when the temperature is high. |
| Coolant system fluid leaks | Leakage in the coolant system causes the boiling heat from the engine to expand the metal and form areas of distorted rotor surface. |
| Overheating rotor material | Brake pads failing to grip the rotor can cause excessive heat to be applied to it. As a result, you can get hotspots or cracking on the rotor. |
| Incorrect installation | Suppose you install the components in the brake system incorrectly. In that case, the excessive wear and tear on one side of the rotor may cause hot spots. |
| Inadequately torqued rotors | Inadequately torqued rotors can lead to uneven pressure during braking. They are another reason for deformed and warped rotors with hot spots (5). |
| Worn or low-quality brake pads | Using low-quality brake pads or worn brakes can cause overheating and, eventually, disc failure due to corrosion of caliper pistons and the brake pad material. In extreme cases, you may see a blown head gap between pad and the rotor. |
| Improper ventilation | The brake system needs proper ventilation to cool down. When it lacks, the overheating will invite hot spots, especially during heavy braking scenarios (6). |
Some other causes are defective master cylinder assembly, damaged calipers or brackets, and lowered tire pressure.
How to Get Rid of Hot Spots on Rotors – Steps to Follow
In this part, I will share dealing with rotor hotspots. You can eliminate the existing hot spots or prevent them from happening in the future.
Elimination of Hot Spots
You can start by cleaning any rust or dirt using a wire brush. Otherwise, sand the rotor until it feels smooth (7).
For minor hot spots, resurfacing the rotors can be an effective solution (4). You can remove uneven wear and restore a flat, smooth surface for the brake pads to contact. However, this method is applicable if the rotors are thick enough to remain above the minimum thickness specification after the process.
If you get severe hot spots, I suggest replacing the rotors. To replace them, first, remove the wheel and caliper to access the rotor. Then, inspect and clean the caliper and bracket. Next, install the new rotor and gradually reassemble the components.
You may choose performance rotors as replacement. They are typically made from better materials than stock ones. Also, they may have design features like drilled holes or slots to improve heat dissipation.
Remember, proper bedding in the new rotors and pads ensures even wear and prevents future hot spots.
Prevention of Hot Spots
Well, you should always use high-quality brake pads. They will easily withstand friction while contacting the rotors during braking. Also, they will stay intact against high temperatures. Look for pads that offer a good balance of performance, longevity, and minimal rotor wear.
While installation of brake pads and rotors, you need to be careful. Notably, the assembly should be secure enough so that any uneven wear and tear does not appear. If you have any concerns, you may discuss them with a mechanic or check the car manual to select and install the suitable brake pads.
Regular maintenance and brake system inspection are the best way to prevent hot spots. By maintaining rotors, I check the brake pads’ thickness and ensure the correct brake fluid level. If you find them degraded over time, take essential steps.
If you have a habit of aggressive driving, for instance, sudden braking, please control it soon. It will prevent the production of excessive heat and, in time, the formation of hot spots. Please, avoid putting an extra load on your vehicle unnecessarily. In this way, you can maintain optimal pressure on the brake system.
Then again, I suggest you use coolants regularly to maintain the correct engine temperature. It will keep things cool and prevent overheating. For a better solution, you may apply a thin layer of high-temperature grease on both sides of each rotor. It helps to reduce friction and ensure even heat dispersion (3).
After all, heat treatment can significantly reduce the chances of rotor cracking and the development of hot spots (8). Once again, always ensure proper torque. This is because improper lug nut torque can cause lateral runout – another significant reason for hot spots (9).
Frequently Asked Questions
- Q: Can I turn rotors with hot spots?
- A: Turning them up can be a temporary solution if you have such rotors. But for the long term, you may follow the steps I have mentioned in this blog.
- Q: What causes rotors to burn?
- A: They can burn due to excessive friction between the rotor and the brake pad or shoe.
- Q: Do I need to replace the overheated brakes?
- A: If you see warps, cracks, or other damage on rotors, you may need to replace them soon.
Final Words
Now, we are at the end of the discussion. I hope you have learned everything regarding hot spots. In this discussion, I have explained how to get rid of hot spots on rotors easily. More precisely, you have learned the causes, identification, elimination, and prevention of rotor hotspots.
I think you can start following the steps I have suggested now. Thus, if you have enjoyed reading it, leave your feedback in the comments section.
Thanks a lot!
