Car skidding across the road when you hit the brake pedal?
This is a scary situation all drivers want to avoid. It typically happens due to a stuck caliper, slippery surface, or faulty ABS system.
Terrified about your brakes locking up again?
Don’t worry!
We’ll help you gain some traction on this problem by discussing the causes behind locked-up brakes and how you can prevent them to avoid accidents in the future.
This Article Contains:
- What Is a Brake Lock-Up?
- 9 Concerning Causes Behind Your Brakes Locking Up
- What Should You Do If Your Brakes Lock Up While Driving?
- 3 FAQs about Locking Brakes
What Is a Brake Lock-Up?
“Brake lock-up” occurs when the friction of your brakes overcomes your tire’s traction on the road.
While both front and rear brakes can lock up, it’s a more common issue in the front brakes. This is because they handle more braking force than the rear wheels due to the forward weight transfer when stopping.
There are two situations in which brake lock-up occurs:
- On pressing the brake pedal: This typically occurs when you brake hard to avoid an accident. However, it can also occur when braking on a slippery surface and even during gentle braking to stop slowly.
- Without pressing the brake pedal: Issues with the braking systems (like a damaged brake hose) result in residual hydraulic pressure, which causes the calipers or wheel cylinders to activate.
Wondering why this happens?
Let’s discuss the common causes.
9 Concerning Causes Behind Your Brakes Locking Up
Here are the problems that result in locked brakes:
1. Stuck Brake Caliper or Wheel Cylinder
In disc brakes, the caliper and brake pads create friction with the rotor to help slow down the vehicle. Meanwhile, in cars with brake drums, the wheel cylinders force the brake shoes against the drum.
However, your brakes might lock up if these essential disc and drum brake components get stuck. Here’s why:
- In disc brakes: Corrosion, faulty caliper bolts, and seized caliper pistons can cause the caliper to get stuck. The caliper will push the brake pads against the rotor, locking the brakes and wearing down the pads.
- In drum brakes: Corrosion may cause the wheel cylinder to get stuck, stopping the brake shoe from disengaging and resulting in continued brake pressure.
2. Overheated Brakes
Excessive hard braking results in abnormal friction, which produces heat. An overheated braking system can cause the hydraulic fluid to boil and metal components to expand, leading to a lock-up.
Note: It’s more common for drum brake systems to overheat because of their enclosed structure.
3. Slippery Surfaces
Slippery road conditions reduce the tires’ ability to generate traction. This causes the friction from braking to overpower low tire traction, leading to the brakes locking up when you press the pedal.
4. Dirty or Incorrect Brake Fluid
Contaminated (containing water or dirt) or incorrect brake fluid can cause corrosion in the brake hoses.
A damaged or blocked brake hose can prevent the brake fluid from returning to the master cylinder, maintaining continuous hydraulic pressure. This can cause a lock-up which will also result in worn brake pads.
5. Stuck Parking Brake
The parking brake (emergency brake) works independently of the main hydraulic braking system. It uses a cable system to either engage the caliper piston to press the brake pads against the rotor (in disc brakes) or push the brake shoes against the drum (in drum brakes).
However, if your emergency brake is stuck and you press your brake pedal, the excessive braking force may cause a lock-up.
6. Malfunctioning Anti-Lock Braking System
The anti-lock brake system (ABS) uses information from the wheel speed sensors (ABS sensors) to prevent a brake lock during sudden stops. It does this by pulsing the brakes (rapid application and release of brake pressure).
However, broken wheel speed sensors may not relay correct information about the wheel speed, which may prevent the ABS from pulsing the brakes, leading to a lock-up. When this happens, the ABS brake light will also come on.
7. Worn-Out Tires
Worn tires lose their ability to grip the road effectively, causing your brakes to lock up easily when you press the brake pedal. When this happens, your wheels will stop rotating, but the vehicle will continue to slide forward.
8. Faulty Brake Booster
A power brake booster amplifies the force applied to the brake pedal, which makes braking easier for the driver.
However, a stuck brake booster will continue to apply force to the brakes regardless of the driver’s pedal input. This excessive braking force can cause your brakes to lock up
9. Road Debris
When debris (like rocks or dirt) gets lodged in the caliper, it can prevent the brake pads from disengaging the rotor. This causes your brakes to lock up, resulting in worn brake pads. In drum brake systems, the wheel cylinders can get stuck, applying continuous pressure on the brake shoes.
Now that you know what causes a lock-up, let’s explore how you can handle this brake issue on the road.
What Should You Do If Your Brakes Lock Up While Driving?
If you have ABS brakes, keep steady pressure on the brake pedal. You may feel the pedal vibrate and see the ABS light illuminate, signaling that the system is pulsing the brakes to prevent lock-up.
But if you don’t have ABS brakes, then there are two steps to follow:
- Reduce brake pressure: Take your foot off the brake pedal to allow the pads to release, enabling the wheels to spin and regain traction.
- Pulse the brake pedal: Press the brake pedal repeatedly to help the pads generate stopping power without locking the brakes.
Got more questions about brakes locking up?
Slide into the FAQs below.
3 FAQs about Locking Brakes
Here’s everything else you need to know about this brake issue:
1. How Do You Prevent Your Brakes from Locking Up?
Preventing a brake lock-up depends on what’s causing the issue. However, there are some general guidelines you can follow:
- Regularly service your brakes: Have a mechanic inspect your brakes once a year and replace them every 30,000 to 70,000 miles.
- Avoid aggressive braking: Repeated hard braking increases the likelihood of brakes overheating and locking up.
- Clean your brakes: This prevents debris and corrosion buildup from interfering with components like the wheel cylinders or brake pads.
2. Should I Drive If My Brakes Are Locking Up?
If you regularly experience a brake lock-up or believe you may have a brake problem, stop driving immediately and contact a mobile mechanic. Driving with unreliable brakes is dangerous as you’ll have less control over the vehicle.
Tip: Even if you don’t have a brake problem, it’s best to avoid driving on slippery roads and continue your journey only when conditions improve. However, if you’re already on the road, drive carefully and avoid slamming the brake pedal.
3. How Much Does It Cost to Fix Brakes That Lock Up?
The cost of fixing brake issues depends on the faulty component causing the lock-up.
Here are some estimates (including parts and labor):
- Tires: $50 to $1000 per tire
- Brake line: $65 to $250 per line
- Parking brake: $160 to $650
- Brake caliper: $730 to $880 per caliper
- Brake booster: $200 to $1250
- Anti-lock brake system: $980 and $1040
Avoid Skidding to a Halt with AutoNation Mobile Service
Several vehicle issues, like a faulty ABS or a stuck caliper, cause a brake lock-up when you hit the pedal.
If you experience a lock-up, have a mechanic look at your brakes immediately, as you may be driving with a significant safety hazard.
Worried about your brakes locking up while driving to the mechanic?
AutoNation Mobile Service mechanics can fix your brakes from your driveway. We’re available seven days a week, and all repairs come with a 12-month,12,000-mile warranty.
Contact us for any brake issues and all your vehicle maintenance needs.