Sometimes drivers experience car jerks when they press the brake pedal. There are a few causes why this happens, but the most common causes are a new pair of brake pads you just installed or your current brake pads are heavily worn.
Usually, a car that jerks when you brake is, most often, a cause of a problem with the braking system, especially right after replacing the discs or drums because of a poor-quality spare part or improper installation.
Also, if the brake pads are worn down to the metal, then jerks begin when a cast-iron disc is seized by the steel base of the pads.
There are also other reasons for car jerking that can even cause hits on the steering wheel. So let’s see the reasons why your car jerks when you press the brake pedal.
Bent brake discs
In most cases, brake discs will be bent after a sudden cooling, specifically, when you drive and hit the brake several times, the discs will be hot and on the road, you will go to a car wash or you will encounter a puddle with cold water.
As a result, the brake disc temperature will suddenly drop, and, if the brake disc material is low-quality, then the chances to change its shape are very high.
Usually, brake discs must be more than 20 mm thick, and if they are not then you should change them both.
There are two solutions to this problem. You can go with the brake discs at a specialized car workshop and straighten them back like in the video below. Or, a much wiser solution for this would be just to replace the discs with brand new ones made from high-quality material.
Changing the brake discs you should change the brake pads too.
Change in the geometry of drum brakes
Similar to deformed brake discs, changes in shape can appear on the drum brake as well due to sudden cooling. It is recommended to change the drum brakes with new ones.
The brake discs are installed wrong
If the mechanics from the car workshop you went to for a brake disc change installed them wrong, this can cause friction against the pad. As soon as possible you should get this fixed.
Worn brake pads
One of the most common causes, is worn brake pads can cause the car to jerk when braking. Other signs that confirm brake pad wear are the whistling they emit when you brake and also the squeaks, which are special metal antennae that rub against the discs, causing a squeak and thereby signaling the car owner that it is time to change the brake pads.
The only solution is simple, you need to change the brake pads with high-quality ones.
Sticking brake pads
The cause of the brake pads is quite rare, however, this problem also caused the car to jerk not only when braking, but also while driving. As a solution, you need to check the brake pads and the calipers. In most cases, the brake pads will need replacement.
Calipers are worn
This problem occurs in cars with high mileage, or in cars where maintenance was poor. Calipers wear off as time passes and they will become loose. In this case, the repair is not possible, you need to change the calipers. Remember to lubricate the new parts after installing them.
Differences between the hardness of the brake discs and the pads
This will mean that you have installed soft brake discs and hard brake pads, causing the pads to damage the discs. So, you need to be careful when choosing the right brake discs.
In this case, we refer to bushings from the rear suspension. If they are worn, often the car will jerk when braking.
Wheel bearing play
This issue will cause the wheels, especially the front wheels, to vibrate when braking. The best solution is to change the wheel bearing
Rust on the brake discs
You have probably noticed that if you do not drive for a longer time, a small layer of rust will form on the brake discs. This is especially true if you live in an area with high humidity.
The simplest solution is not to let the car sit too long without driving it. If you do this, then the rust layer will be consistent, which will make us opt for the more expensive solution, that of changing discs. You can opt for the solution presented in the video above, but it is not recommended.
If the rust layer is very thin, it will disappear naturally when you drive and brake for the first 12-18 miles. This will cause the car to jerk when you brake.
Air in the braking system
If air is present in the braking system, then this means a reduced efficiency in braking, often leading to jerks when you press the brake pedal. The solution to this problem is to remove the air from the system and add braking fuel.
There are some reasons why your car jerks when braking. So to find out what is causing it, you need to perform some checks in a car workshop that is using the proper equipment.
Being related often to problems with brake discs and brake pads, you can’t figure it out just by observing. This issue will not cause just discomfort, but it can represent a real danger on the road.