Why do brake rotors warp

To prevent the brake rotors from becoming glazed over with brake pad material, be mindful of how much braking the vehicle is doing compared to what is done during normal operation.

When going downhill for prolonged amounts of time, try to control the speed of the vehicle by shifting the transmission into a lower gear. For automatics, the only option is usually to shift into "3," while vehicles with a manual or other shiftable transmission can decide on the best gear to use based on the engine's revs.

When the brakes are hot, never sit with the brake pedal hard down on one spot. Also, when the brake pads are first installed they should be properly broken in to ensure they don't leave too much material on the brake rotor. This usually involves getting the car up to road speed and then braking until it is traveling ten miles per hour slower.

After this is done a few times, you can work your way up to braking to a complete stop. The first few full stops after that should be done with care. This allows the brake pad to perform better during hard braking further down the road.

The steps that can be taken to prevent excess wear on the surface of the brake rotor are similar to the steps for avoiding glazed rotors. Be sure to avoid hard braking when the brake rotors have gotten hot from prolonged use. If the brake rotors are glazed over, you may hear excessive squeaking when the brakes are applied or even smell burning rubber. If the braking suddenly becomes jittery and inconsistent, the brake rotors should be the first suspect.

This article originally appeared on YourMechanic. Autoblog is partnering with YourMechanic to bring many of the repair and maintenance services you need right to you. Get service at your home or office 7 days a week with fair and transparent pricing. We get it. The object of this exercise is to measure run out, so mount the rotor, and torque it down.

Check both sides of the rotor with dial gauge while rotating the rotor, and mark high spots on both the rotor and the hub. If the run out value differs significantly from the previous value, rotate the rotor another 90 degrees or one bolthole and recheck the run out.

Have you ever really wondered why all car manufacturers specify a particular torque value for the wheel. All manufacturers go to great lengths to calculate appropriate torque values for each fastener on their products and wheel fasteners are particularly important since they serve a dual purpose, one of which is to stabilise brake rotors when enormous braking forces attempt to deform them.

In practice, the plane of the clamping force that slows the vehicle down is offset from the plane of the clamping force that holds the rotor against the wheel hub. Apart from the fact that air wrenches are generally not calibrated to any particular value, the first use of the wrench causes the air pressure, and therefore, its effective torque to decrease, causing the compressor to kick in, which raises the air pressure in the system again.

The only way to avoid deformation and subsequent run out on brake rotors assuming that the rotors were installed correctly, in the first place , is to use a properly calibrated torque wrench to tighten wheel. In addition, tightening should always be done in a cross-wise aka star pattern , with the two fasteners that are the furthest away from each other being tightened in pairs, and preferably in two steps to load the rotor evenly.

There are many online resources that describe comparison tests in terms of the repeatable accuracy of torque sticks, and it turns out that few brands score well in this department. Although this article does not pretend to be the last word on uneven brake rotor wear, we hope that you find the information presented here both informative and useful, and that it will help you diagnose brake pedal pulsation issues with confidence.

Toggle navigation Navigation. Because they must absorb a ton of friction, brake rotors must be constructed to withstand very high levels of heat. The heat generated by brake rotors also has to be designed to dissipate quickly because the brakes are used so frequently while driving. Brake rotors work as part of an integrated system along with the calipers and brake pads. When the operator of a vehicle presses down on the brake pedal, this causes the calipers to clamp the brake pads down on the brake rotors.

The brake pads push against the moving wheels to slow them. The majority of brake rotors available on the market are constructed from gray cast iron. This is because gray cast iron disperses heat well, which is the single most important aspect of brake rotor construction. While most brake rotors are made of iron, there are also ceramic rotors used that have the following advantages over metallic ones:.

There are many benefits to using ceramic brake rotors over metallic brake rotors, but ceramic rotors tend to be much more expensive than metallic rotors. Metallic rotors might be less expensive but wear more quickly and produce more brake dust. A good compromise can be semi-metallic rotors, which fall between metallic and ceramic rotors in price and offer some of the advantages of ceramic rotors at a lower cost point. Another option for rotors is a rust-proof coating, which increases the durability of the rotor as well as maintains its shine for added cosmetic value.

When a brake rotor becomes warped, the surface of the rotor becomes rough and uneven. The primary cause of brake rotor warping is excessive amounts of heat build-up when braking. Excessive heat can affect the brake rotors negatively in two ways:. In either case, the rotors are damaged by excessive heat, and this damage, in turn, affects the stopping performance of the vehicle. Hard braking alone does not cause brake rotors to warp, as long as braking is done when the car is already driving at a lower speed.

However, repeatedly braking from high speeds, such as the maneuvers performed on a racetrack, causes heat to build-up faster in the braking system. If a driver has to perform an emergency stop and a hard brake with their vehicle at a low speed, such as twenty or thirty miles an hour, this should cause no damage to the braking system.

However, if a driver is repeatedly slamming to a stop from higher speeds such as forty miles per hour or above, this is eventually going to cause the brake rotors to warp. It is sometimes easy to skimp on maintenance for vehicles, especially for those drivers on a tight budget, but the brake system is not a system you want to try and limp along.

If you have issues with your brake rotors, it is a serious safety hazard, and the vehicle should not be driven until the rotors are repaired or replaced. Consider different types of rotors to give you the best cooling brake system available for your vehicle to ensure that brakes cool properly and to guarantee there is no more warping.

After replacement, you will need to break in the rotors and pads according to the manual or the guidelines provided. To keep the rotors in the best working order, be sure to lubricate the rotors, pads, and wheel hubs properly as needed, and refrain from driving into puddles when your rotors are overheated due to excessive braking.

This entry was posted in Uncategorized on January 31, by cdr. Toll Free How to Prevent Brake Rotor Warping. Install a High-Quality Brake Rotor If your brake rotors are already warped, you need to replace them with new ones. Install Brake Pads If your brake rotors have been warped for a long period, you might need to consider installing new brake pads. Break in the Pads and Rotors Once you have installed new brake rotors and pads, you must break them in properly.

Breaking in Brake Pads Start driving and continue until you reach 40 miles per hour. Engage a hard brake once you reach 40 mph, but do not come to a complete stop. A hard brake is where you "slam" on the brakes. Start accelerating again to 50 miles per hour and slam on the brakes again just until the ABS has been engaged approximately 10 miles per hour. Again, do not come to a complete stop.

Repeat the above two steps for a total of four times. So far, you should not have completely stopped yet. Accelerate to 65 miles per hour, and then take your foot off the gas and coast to 15 miles per hour. Once at 15 miles per hour, brake slowly until you come to a complete stop.

Park the vehicle and let the car cool off for 20 minutes.