Why Do Brake Pads Rub Against Rotors?
Brake pads often rubbing against rotors is a common issue that can cause a jerking sensation when pressing the brake pedal or even a continuous noise. However, this problem is not one-size-fits-all; it can arise from several reasons. Understanding the causes can be instrumental in addressing and fixing this issue efficiently.
Common Causes
Once you recognize the signs of an issue, it is crucial to investigate the potential causes. Here, we explore the most common reasons behind brake pads rubbing against rotors:
Worn Brake Pads
One of the more straightforward causes is worn brake pads. As brake pads wear down over time, they can become too thin or lose their shape, resulting in poor fitment within the caliper. This misfit can cause the pads to rub against the rotor continuously, even when braking is not applied.
Misalignment Issues
Misalignment of the brake caliper or incorrect installation can be another culprit. If the caliper is not aligned correctly or the pads are not seated properly, it can force the pads into constant contact with the rotor, even when the brakes are not engaged.
Sticking Caliper
A stuck or seized caliper can prevent the pads from retracting properly after braking. This can lead to constant contact between the pads and the rotor, resulting in increased wear and noise.
Warped Rotors
If the rotors become warped due to excessive heat or wear, they can cause uneven contact with the brake pads. This can result in rubbing and a jerking sensation during braking.
Debris and Foreign Objects
Dirt, grime, or foreign objects lodged between the pads and rotors can also lead to rubbing and noise. These contaminants can interfere with the proper function of the brake pads, causing them to rub against the rotor.
Incorrect Installation
Improper installation of brake pads or rotors, even by professional mechanics, can lead to improper spacing and rubbing. This can often be a result of measuring tools not being accurate or simple human error.
Brake System Issues
Finally, issues with the brake system itself, such as air in the lines or a damaged brake line, can lead to improper functioning of the brake system. This can cause components to behave erratically and result in rubbing issues.
Addressing the Issue
When you experience brake pad rubbing against the rotors, it is advisable to take your vehicle to a professional for inspection. A mechanic can diagnose the issue and provide the necessary solutions to get your brakes working seamlessly again.
What Happens When You Press the Brake Pedal?
Understanding the brake system is essential to grasp how the issue of rubbing brake pads arises. When you press the brake pedal, a series of actions occur:
Pedal to Fluid
Pushing your foot on the brake pedal initiates a process where the pedal pushes brake fluid from the master cylinder to the front and rear calipers. The master cylinder, filled with brake fluid, generates pressure through the brake lines that connect it to the calipers.
Caliper Action
The pressure travels through the brake lines and reaches the caliper pistons. Each caliper piston, when pushed by the brake fluid, extends and pushes the inboard brake pad against the rotor. This applies pressure from one side of the rotor. At the same time, the pressure from the caliper piston moves the outboard pad towards the rotor, clamping it from both sides.
Once the brakes are released, the caliper piston retracts, and the pads are pulled back into their resting position.
Conclusion
Brake pad rubbing against the rotors can be a sign of serious underlying issues that need to be addressed. Whether it's worn components, misalignment, or any other problem, taking your vehicle to a professional for a thorough inspection is the best course of action. By understanding the causes and the mechanics of the brake system, you can better navigate these issues and ensure your vehicle's safety and reliability.