It’s safe to say that when your brake rotors start to show cracks, they’re pretty much done for. A cracked rotor is completely unsafe to drive on and should be replaced immediately. What causes such extreme damage though?
Generally, cracking occurs mostly with rotors that have been drilled. Whilst drilled rotors do provide loads of braking performance improvements, they are more prone to cracking. More specifically, rotors that would have started out as blanks and had the holes drilled into them rather than those that have been casted with the holes in them. Cracking in these types of rotors has a lot do with structural rigidity. Drilling through a rotor greatly compromises its strength, especially if no care has been taken to not drill through the support vanes of the rotor, making cracking pretty much an inevitability. DBA’s cross-drilled brake rotors are quality-assured as they’re casted with the holes in them meaning you’ll be hard-pressed to have this type of damage come about.
Heat dissipation also has a lot to do with why cracking in drilled rotors occur. As rotors get hot under usage, thermal expansion occurs and if the drilled rotor has been manufactured incorrectly, they begin to crack as the heat dissipates. This is due to the fact that the thermal energy is centralised around the holes rather than spread evenly across the rotor. Again, this is unlikely if the rotor has been casted with holes already present.
Another reason is to why rotors may begin to crack is the build-up of gas and debris. As the brakes are engaged, gas and debris collects in between the brake pads and rotors which can cause the rotors to crack over time. Slotted and drilled rotors can work to expel any built up gas and debris, but mindful of the quality of any drilled rotors you might consider.
Photo Credit: Home Shop Machinist
It’s important to remember that once a rotor has started to crack, they pose an enormous risk to your safety and must be replaced as soon as possible. You also need to be careful with drilled rotors as if they’ve not been manufactured properly, cracking can become a very likely possibility. With DBA brake rotors, you are quality-assured against such a detriment to your safety.