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Warped Brake Rotors
The reason your car shakes when hitting the brakes is because your rotors are warped. Brake rotors are commonplace on most vehicles nowadays.
Brake rotors are circular pieces of metal that are attached to your axles.
Your rotors are usually spinning at the rate of your axles, which is basically the speed of your car.
When you press down on your brake pedal with your foot, your brake pads grab onto your moving rotors.
If your rotors aren’t perfectly round, they will transfer vibrations to the rest of the vehicle through the brake pads. If you have worn brake pads, the vibrations your car experiences will be more severe.
You will probably feel vibrations not only in your car but also in your brake pedal.
It’s easier to imagine a rotating dinner plate. Now pinch your fingers around the lip of the dinner plate to try and get the plate to stop rotating.
If the plate is perfectly round, the plate will stop smoothly.
If the plate is warped, it will cause some vibrations in your hand. This is essentially what happens with rotors.
Rotors can become warped for a number of reasons, but the most common reason is excessive heat.
Heat can cause a brake rotor to become unround and cause vibrations throughout your vehicle.
A brake rotor can get hot with hard braking in stop and go traffic. This braking will cause friction on your rotor which will cause the rotor to heat up and eventually warp.
You will feel front rotor warpage vibrations in your steering wheel and rear rotor warpage vibrations in your seat.
Your front rotors are connected to your steering wheel through linkage so that’s why you’re more likely to feel vibrations in your steering wheel if your front rotors are warped.
Once you have a warped rotor, you will either need to replace it, or get it machined.
Your brake pad also can cause car shaking if the vehicle has a warped rotor.
For example, if the brake pad is worn, or the brake pad is on its last legs, the padding that usually mitigates vibrations is missing, and the vibrations will go right through the brake pad to the rest of the vehicle.
Warped rotors can add extra stress on your wheel bearings as well, since your wheel bearing will be taking the brunt of the warped rotor action. As well, warped rotors can cause sticking brake calipers if the warped rotor is not taken care of quickly.
Unbalanced tires will cause your vehicle to shake when driving at around 30 mph or faster. If a tire is not perfectly balanced, it will cause vibrations once the tire is spinning at a fast enough rate.
This vibration will be felt when accelerating and while braking. Depending on which tire is unbalanced, you will feel the vibration in the front of your vehicle or the rear.
For example, if your front tires are unbalanced, you will feel a vibration in your steering wheel when driving. If your rear wheels are unbalanced, you will feel the vibrations in the seat of your pants.
If all four tires are unbalanced, you will feel vibrations in both the front and rear of your vehicle.
But, again, unbalanced tires cause vibrations when driving and braking both. If your vehicle is just experiencing shaking while braking, look at your rotors.
If you have vehicle shaking when driving, accelerating, decelerating, and braking, look at your wheel balance.
How To Fix Rotors
There are a couple different methods to fix rotors that are causing your vehicle to shake. The first, most common way to fix the issue is to replace the rotors.
Rotors are usually around $60 per each rotor so replacing them is usually the most cost effective way to repair the issue.
That’s because machining them costs around $40, and you aren’t getting new brake rotors with that cost.
The second most common method to fix warped rotors is to machine them. Machining rotors requires hooking them up to a lathe, entering exact specifications, and having the lathe cut the rotor until it is perfectly round again.
I’ve worked in a shop that still cuts rotors, but the majority of shops today suggest replacing rotors instead of cutting them for cost effectiveness.
Cutting rotors is something of a dying art, but you may find a shop that will abide by your wishes if you specifically ask for your rotors to be cut.
Can You Drive On Warped Rotors?
Yes, you can technically still drive on warped rotors. The rotor will still stop the vehicle effectively even if it’s warped.
The only thing you will have to worry about is the vibrations.
But as a mechanic, the best advice I can give you is to replace warped rotors as soon as possible.
Vibrations while braking can, if the vibration is serious enough, turn into a major problem. Once a rotor starts to warp and no action is taken, the rotor’s condition will only get worse.
And rotors can become so bad that they literally start to fall into pieces. So if you notice minimal vibrations while braking, it’s ok to drive on them for a little while.
And when I say a little while I mean, maybe a couple rides to work and then a trip to the mechanic or auto parts store.
But anything more than that is risking too much. So while yes, it’s possible to drive on warped rotors, it’s not advisable. You should repair warped brake rotors as soon as possible.
How Long Do Rotors Take To Change?
A brake job usually takes around 30-40 minutes to complete. This is the time it takes the mechanic to do the job if he’s replacing all four rotors. And when you replace rotors, it’s usually recommended that you replace the brake pads at the same time.
This 30-40 minutes is the time it takes the mechanic to take off the tires, take off the brake calipers, remove the old rotors, install the new parts, re-install the tire, pump the brakes, and test drive the vehicle.
The 30-40 minute time frame is what a brake job takes if nothing goes wrong. More often than not, a bolt won’t come undone or a clip won’t sit right causing a mechanic to spend more time than the normal time rate.
If your brake calipers get stuck onto the rotor expect the time window to increase even more.
But most of the time, things go smoothly, especially if your car is a newer car. A newer car has less rust and the parts are usually more well maintained if you do oil changes and tire rotations regularly.
If you do the job at home on jack stands, you have to factor in more time since you have to jack each wheel up individually.
If you do a 4 wheel brake job at home, expect to spend 60-90 minutes on the job, and allot more time for yourself if you have never done a brake job before as a lot of the brake set up might be confusing and overwhelming as a first time DIYer.
Remember to always lube your brake pads as well. Brake pads that aren’t lubed properly can cause squeaking.
Should I Get My Tires Balanced When I Get A Brake Job Done?
Yes. While it isn’t necessary to get your tires balanced when doing a brake job, as a good rule of thumb, you should get your tires balanced any time they come off the car.
The balance of a tire is very finicky and can alter with the slightest change such as hitting a bump. So it’s good to stay on top of your tire balance by getting them balanced anytime they come off your tire.
Also, ask the mechanic to clean your hubs when your tires are off. A lot of mechanics will do this for free, and it’s a great way to provide maintenance to your vehicle that keeps the wheels and hubs fresh for the next time you take them off.
Otherwise, there’s the possibility that your wheel will stick to your hub and will give your mechanic a hard time when he goes and takes your wheels off.
About The Author
Christopher Sparks has been servicing vehicles since 2012. After completing the automotive studies program at Camden County College, he was awarded an Associates's Degree in Applied Science. His first job was a lube-tech at Jiffy Lube, and is currently an independent B-Technician servicing vehicles for the United States Postal Service. Christopher is ASE certified and loves rebuilding engines.Read more about Christopher Sparks