Why does my car vibrate and shudder when I brake?
Brake shudder is the vibration or shaking that you feel through the steering wheel and/or the brake pedal when you brake in your car. Brake shudder usually arises as a result of issues with the brake discs (also referred to as brake rotors). When your brake discs are unevenly worn the brake pads come in contact with the flat spots present in the disc’s surface which causes the vibration that you feel, also called brake shudder.
This kind of uneven wear of your discs can be the result of a number of things. For instance, the brake calipers not operating correctly, the rotors not having been installed properly or the proper bedding-in process not having been applied if new brake pads have been installed recently.
Despite this being the most common cause of shuddering brakes, there are a few other possible explanations as to why you are experiencing this symptom.
What are the common reasons a car shudders or shakes when braking?
Unevenly worn brake discs
Risk level – High
What to do – Book your car in for a vehicle diagnostic check or a brake disc replacement as soon as possible
Unevenly worn brake discs are a common cause of vibrating brakes. This uneven wearing down of the brake discs could be a result of them being installed incorrectly, or your brake calipers not operating properly. The vibration that you feel, also called brake shudder, occurs
when the brake pads come in contact with the flatter, more worn spots in the disc’s surface. Generally, when shudder is felt through the steering wheel this indicates that the front brake discs need to be looked at. If the vibrations are felt under your foot, through the brake pedal, this usually points towards an issue with the rear brake discs.
Wheel alignment issues
Risk level – Medium
What to do – Check whether your car is dragging to one side when driving. If it does, this could indicate that your wheels need to be realigned.
Another common cause might be issues with your vehicle’s wheel alignment. If you notice that you experience shuddering when you brake at high speeds, you could have a problem with your alignment.
To test this, drive your vehicle at this speed at an opportunity when there are no other vehicles around. Remove your hands from the steering wheel for a couple of seconds (keeping them close by for safety) and check if the car drags towards the left or right. If there aren’t any alignment issues, you’ll continue traveling straight. But if your car pulls to one side this could indicate that your vehicle needs to be realigned. To fix the issue, your car will require a full inspection as to whether it needs a two-wheel or four-wheel alignment.
Dirty or worn brake pads
Risk level – Medium to High
What to do – Visually inspect your brake pads for signs of wear or dirt. If they need to be cleaned or replaced, you should have this work carried out by a mechanic as soon as possible
Another common cause of a shaking sensation when braking is brake pads being filled with oil, dirt or other materials. When these substances stick to the rotors, they can cause an array of vibrations, leading to your vehicle shaking when you press the brakes.
This shaking can also happen if the pads are warped, damaged, or excessively worn. If this is the case the brake shuddering will likely be accompanied by a loud grinding noise when braking. The solution is to replace your brake pads as soon as possible as worn brake pads can be very dangerous.
How to fix vibrating brakes?
If the cause of the shaking brakes is related to unevenly worn brake discs, they need to be machined to iron out the flat spots or replaced completely depending on the condition of the discs. Similarly, if the issue is related to the brake pads, these will need to be cleaned or replaced by a mechanic to stop the vibrating brakes. If the cause of the brake shudder in your car is found to be issues with wheel alignment then this will need to be fixed by a mechanic.
Is brake shudder dangerous?
If your shuddering brakes are being caused by damaged or worn brake pads or discs, continuing to drive your car is very dangerous. If you continue to drive with worn-out pads, your braking performance will deteriorate further. Worn out brake pads should be replaced immediately. A visual check should confirm when the pads need replacing, or when a sensor triggers a dashboard warning light.