I was driving around the other day and as I was about to make a complete stop, my steering wheel started shaking as soon as I pressed my brake pedal.
To be honest, I didn’t know what was causing the issue right away. So, I talked to a couple of mechanics and did research online. Here is why my steering wheel is shaking when I hit the brakes.
Why Is My Steering Wheel Shaking When I Brake?
Why is my steering wheel shaking when I brake? The most common reason why your steering wheel is shaking when braking is because one or both front brake rotors are warped causing the caliper to wiggle when you apply the brakes. Brake rotors can become warped due to bad quality, drastic temperature changes, or wear and tear.
When you hit the brakes, the caliper applies pressure to the brake rotor’s surface and your car starts to brake. The brake rotor’s surface should be flat in order for the calipers to apply constant and equal pressure. If your brake rotors become warped for whatever reason, the caliper will start to wiggle and your steering wheel will start to shake when you start braking.
Brake rotors can become warped for many reasons. Decent quality brake rotors can withstand temperatures up to 200 degrees Celsius or 392 degrees Fahrenheit. Imagine driving around town and constantly applying the brakes.
The temperature of the brake rotors will increase with each braking. Then, you might decide to take your car to the car wash, or it starts to rain. At this point, you have a heated brake rotor in contact with cold water. The drastic temperature change can make your brake rotors warped.
A warped brake rotor should always be replaced with a new one. You could grind your brake rotor and fix the warp. But, I would recommend that you take this matter more seriously and replace the warped brake rotor with a new one. You shouldn’t save money when fixing a serious car malfunction as braking.
What Causes a Warped Brake Rotor
Driving around with a warped brake rotor will cause your steering wheel to shake when braking. It is both an unpleasant experience and a safety issue. So, what causes a warped brake rotor? Here are some answers for you:
1. Overheating issues
The temperature of the brake rotors increases each time you apply the brakes. Sometimes, during the braking application, the caliper piston can get stuck and it could ”burn” the brake rotors. This is what we call overheating issues.
Other issues that could cause overheating issues on the brake rotors are the pads sticking in the bracket. When this happens, something like burn marks will appear on the brake rotors. That’s gonna be a raised area, especially once the rotor gets hot from driving and it’s gonna cause brake pulsation.
In order to verify that your brake rotor has been warped due to overheating issues, you will have to perform a visual inspection. Remove the wheel and carefully inspect the brake rotors. If you see areas on the brake rotors looking like hot spot lines that are just going straight, these lines are going to build up more and more.
So, when you press the brakes, the caliper will apply pressure on the brake rotors and when it goes over the build-up lines, you are going to feel a braking pulsation. At this point, your braking system has an overheating issue that has to be addressed properly.
2. Rust pits on the brake rotors
If your vehicle has been sitting for a long time, your brake rotors can and will accumulate rust on them. The build-up rust on the brake rotors will cause an uneven surface and your brake rotors will appear warped.
If you see little dimples on the brake rotor, those are actually rust pits. What happens is is after your vehicle has been sitting for a long period of time, it’ll accumulate moisture along the whole braking surface.
As that moisture sits there for a while, it makes its way into the rotor porous materials since the braking rotors are made out of metal. The rust starts making these little pits. Then, once you drive the vehicle, it’ll take off the outer portion of the rust and it’ll just kind of leave all these pits causing an uneven surface. Rust on the brake rotors will most definitely cause a braking pulsation, shaking steering wheel, and even noise.
3. Damaged surface from metal to metal contact
If the caliper piston is stuck in the braking position, it will apply constant pressure on the braking pads against the brake rotor and will damage the rotor’s surface. The way braking works is when you press the brake pedal, the braking fluid travels through the braking pistons making it squeeze the pads against the braking rotor. If the piston is stuck in this position, it will constantly push the braking pads into the braking rotor and will damage the rotor’s surface.
The caliper pistons need to squeeze the braking pads when you press the brake pedal and then retract once you release the braking pedal. You could perform a visual inspection in order to see if your braking pistons are working properly. Also, you can just drive your vehicle as slow as possible and if you hear a grinding sound, you should check your braking system.
4. Wear and tear
Brake rotors can become warped if they are used for too long. How long do brake rotors last depends on your vehicle size, driving style, and quality? In general, most brake rotors will last anywhere between 50,000 to 70,000 miles.
If your vehicle has been sitting for too long, or you have been driving it for way too long without replacing the brake rotors, they can become warped. As I said earlier, a warped brake rotor will cause your steering wheel to shake while braking.
It is best that you change your brake rotors every 50,000 to 70,000 miles. But, I recommend checking the thickness of the braking rotors before replacing them. Depending on your driving style, brake rotors can last even more than predicted.
5. Drastic temperature changes
Each time you apply the brakes, the brake rotor increases its heat. Typically, most braking rotors are built to withstand temperatures up to 209 degrees Celsius or 408 degrees Fahrenheit. So, imagine you are driving around the city and you are constantly applying the brakes. Normally, the brake rotors would get heated.
Then, you take your vehicle to the car wash. Now, you are washing your heated brake rotors with cold water. Washing your heated brake rotors with cold water will cause a thermal shock and your brake rotors will warp over time.
How To Check If My Brake Rotor Is Warped
Measuring the brake rotors for minimum thickness on both the front and rear brake rotors will show if your brake rotors are warped. A front brake rotor that has an uneven surface will cause the steering wheel to shake when we brake. The rear brake rotor will only cause a pulsation in the brake pedal if it’s warped. Here is how to measure the thickness of your brake rotors and check if it’s warped:
1. Gather the required materials for measuring brake rotors
You need to have the right tools in order to measure the thickness of your brake rotors and check if your brake rotors are warped. So, before starting this procedure, make sure that you gather the required materials:
- Safety gloves. I always prefer wearing safety gloves when working on my car because of the many corrosive liquids that can cause skin damage. (See safety gloves on amazon.com).
- Safety goggles. Ever since I accidentally spilled engine oil in my eye, I started wearing safety goggles when working around cars. Please don’t wait for an accident to happen and get yourself some safety goggles. (See safety goggles on amazon.com).
- Car Jack. You will need to lift your vehicle in order to check the thickness of your brake rotors. So, if you don’t have a car jack, you can get one from amazon.com.
- Brake rotor gauge. The measuring of the thickness of the brake rotors is done by a specially designed gauge. I got this electronic gauge on amazon.com and I am satisfied with both the price and the performance.
- Lug wrench. This telescoping lug wrench comes with a 17mm and 19mm socket, which makes it perfect for this job. You can order this lug wrench on amazon.com.
2. Jack up the vehicle
In order to check if your brake rotor is warped, you will need to gain access to the brake rotor by removing the wheel. Park your vehicle on leveled ground and secure the wheels with bricks or wooden pieces. Then, jack up your vehicle and place it on jack stands. To find out what are the jacking points for your vehicle, please read the owner’s manual.
3. Remove the wheel
Remove the wheel by removing the lug nuts. The size of the lug nuts may differ, but in most cases, you will need a 17-millimeter or 19-millimeter drive and a 1/2 ratchet for better leverage.
At this point, one side of your vehicle is lifted. Be careful when applying force to remove the lug nuts as it might start swaying. Safely store the lug nuts and the wheel as you will be reinstalling it later on.
4. Remove the caliper
After the wheel is off, remove the caliper by removing the two bolts located on the backside. Then, safely attach the caliper to the spindle using straps to hold the caliper in a safe position that we don’t stress the hose. Never let a caliper hang on its hose because it will damage it.
5. Measure the brake rotor using the measuring tool
Zero out your brake rotor measuring tool before you start the procedure. Place the micrometer on the brake rotors and take measurements in multiple places. If the measurements of the brake rotor are different in different locations, then it is safe to say that your brake rotor is warped and needs replacing.
The minimum thickness of the front brake rotors is 19 millimeters and eight millimeters on the back brake rotors. Anything below 19 millimeters on the front brake rotors or below eight millimeters on the back brake rotors is considered below specification.
6. Reinstall the parts
After you are done with measuring the thickness of the brake rotors, reinstall the caliper and the wheel. If your brake rotor’s thickness was below the minimum, I suggest you replace your old brake rotors with new ones. Also, while you are at it, you can check the brake pads as well.