Why Does My Car Shake When It Breaks? - OHS Body Shop

Sometimes you may feel a pretty noticeable vibration when you push breaks on a highway. Sometimes your car may start shaking when you pull over at a red light or Stop sign. It feels like the vehicle is crossing some bumps or small obstacles, while it is, in fact, the road is smooth and clear.

So why would your car start shaking then? In fact, there are numerous reasons for this “vibration.” Sometimes it is about an unbalanced wheel. In other cases, the reason is a damaged axle shaft. The lug nuts may also go loose, causing the wheels to wobble, which naturally leads to this shaking when you hit the brakes. 

In any case, once your vehicle starts acting out, you should take it to a qualified mechanic as soon as possible. The problem may be minor and eliminated in a few minutes or can occur something pretty serious or even life-threatening.

In this article, we shall talk about the most common reasons why your car may start shaking when you hit the brakes.

It is all about the breaks.
As we have already mentioned, there can be many reasons why your car may start shaking when it breaks. But most mechanics would recommend you to check the braking system itself once the issue occurs.

The idea is simple – all other issues like unbalanced wheels or loose lig nuts will be noticeable throughout the whole driving, not only when you hit brakes. So if the problem occurs only when the car brakes, the braking system should be the first one to check.

Modern vehicles have two types of brakes:

  • Disk brakes – This type is literally a metal disk that is coupled to the wheel. Those disks are called rotors. Each rotor has a caliper – a clamping device that allows the wheel to rotate freely until you hit the breaks. At this moment, the hydraulic braking system forces the caliper into contact with the rotor, and the wheel slows down. The harder you push the breaks, the stronger is the pressure of the hydraulic system and the faster the car will stop;
  • Drum brakes – In this case, a metal drum attaches to the wheels. Once you push the brakes, the “shoes” force the hydraulic braking system into those drums, causing friction and slowing the vehicle down. 

In both cases, your car may start shaking each time you pull over.

Why do brakes make the car shake?
If you have disk brakes, your car will start vibrating when you push brakes due to some sort of damage to the rotor. The heat and friction caused every time the brake pad applies the rotor will inevitably lead to its wear-off.

The shaking may also occur if your car stays parked for too long. In this case, the area of the rotor under the brake pad mas starts to corrode and collect brake pad material. Once you start driving such a vehicle again, the rusted rotor will have the same effect as a damaged one and cause the vibration.

In both cases, you may try to restore the rotor filling the damage and corrosion away, but if too much material is taken off, the braking system will start wabbling again pretty soon. It is better to check the brakes thoroughly and replace the damaged parts as soon as possible.

In the case of drum brakes, deformation of the drums themselves is the most common reason for shaking. Just like with disks, you can try and restore drums mechanically, but it is essential to make sure that their thickness remains unchanged. In most cases, it is better to replace the drums as well.

While brakes are among the vital systems in your vehicle responsible for your safety, the issues that we have mentioned above are pretty easy to fix. Anyway, a qualified mechanic will always manage to detect the real source of shaking and eliminate it.

Contact OHS Body Shop for a qualified consultation and service from a team of experienced mechanics. Located all over Montana’s Greater Flathead Valley, in Kalispell, Whitefish, Columbia Falls and Polson, our branches provide all sorts of services, from routine check-ups to urgent repairs.