Brakes Locked Up While Parked: Causes, Symptoms, and Solutions
Imagine you have started your car after letting it sit in the garage for a while. You engage the gear, release the parking brake, accelerate the car, and nothing happens. It feels like the parking brake is still engaged, and the car doesn’t seem to move at all.
It is because the brakes locked up while parked. Locked-up brakes mean brake system components aren’t able to release pressure from the wheels. So, the wheel won’t move.
The problem is caused by several reasons. In this guide, we will discuss those reasons, tell you how to diagnose seized brakes, and how to get your car going again. Let’s begin.
Why Do Brakes Get Locked Up While Parked?
When vehicles are parked for a long time, the brakes can get seized. Several reasons cause it, and here is a detailed overview of them.
- Rust and corrosion
- Damaged brake caliper pistons
- Stuck slide pins
- Torn handbrake mechanism
- Hydraulic system fault
Let’s get to know more about these reasons.
Rust and Corrosion-
The main threat to a vehicle sitting for a long time is corrosion. Especially if you park your cars outside, environmental elements will affect the integrity of the car components quickly. As a result, the brake system components will also be corroded over time.
And this corrosion will deform the original shape of the brake components. So, the brakes will get locked up, and the car won’t move. Sometimes, the car can move slightly but won’t drive that well. In other cases, the car won’t move at all.
Damaged Brake Caliper Pistons –
When we brake at high speed, the brake components withstand a very high temperature. And that temperature drops when we accelerate. This frequent temperature change has an adverse effect on brake caliper pistons. Over time, caliper pistons will get brittle to develop cracks.
And when they are not in use, the situation will deteriorate. Pistons or calipers can be broken to seize the brake system, and the vehicle will fail to move. To learn more about how the system works, you can check the design of a single-piston floating brake caliper.
See Also: Can Abs Cause Brake Pedal To Go To The Floor?
Stuck Slide Pins-
To better understand the role of slide pins, here is a detailed image of a regular car braking system from Bendix.
Brake calipers and mounting brackets are attached together through slide pins. When you press the brake pedal, brake fluid travels through the brake line to the piston. So, the calipers move along the slide pins and pull the other side toward it. And the brake pads are pressed against the rotor disc.
These slide pins can get stuck when left unused for too long. As a result, the calipers can’t move along the pins, and the brake pressure won’t be released from the rotor disc.
Here is a video to help you understand the whole process.
Torn Handbrake Mechanism –
In older vehicles with mechanical parking brakes, brake calipers or pistons won’t be the culprit always. Instead, you will have a faulty handbrake mechanism to prevent your car from moving. Handbrake mechanisms depend on simple levers and cables to engage the parking brake.
The handbrake cable can get rusty when you park the car for too long. And the constant pull on the line will tear it over time. So, even if you disengage the parking brake after a long break, the car won’t move.
Hydraulic System Fault –
Brake systems depend on hydraulic fluids to engage or disengage. When you press the brake pedal, hydraulic fluid from the master cylinder gets pushed through the brake hoses. It reaches the caliper pistons and engages the brake. When you release the brake pedal, the fluid should return to the master cylinder.
But if there is a faulty valve or jammed hose, the fluid can’t fully get back to the master cylinder. As a result, the hydraulic pressure won’t be removed from the brakes. And you will feel like the brake is still pressed.
Read Also: Understanding The Acura VSA Light
What Are The Symptoms of Locked-Up Brakes?
The signs of brake seizure will be different depending on the parking period of the car. Here are a few symptoms to identify locked-up brakes.
The Vehicle Won’t Move
When the brakes are locked, the vehicle won’t move in any direction, even if the handbrakes are disengaged. It will feel like the brake pads are pressing the rotor disc.
Vehicle Pulling Aside
Even if the car moves after a bit of struggle, it will pull aside when you press the brake.
When the brakes are locked up, and you want to drive the vehicle forcefully, the components will heat up. So, you will get an acrid smell from brake components.
As the deformation of components causes the brakes to lock up, you will hear squealing or growling noise from the brakes.
Read Also: Understanding Why is My RPM at 1 When Parked
What Should You Do If Brakes Locked Up While Parked?
You need to take different actions depending on the situation. Follow the steps below to get a car with locked-up brakes going.
Clean the Rust
Check the brake disc and calipers for signs of rust. If the rust layer isn’t that thick, you should turn the car on. Slowly press the accelerator to drive the car forward a bit. Then, put it into reverse and drive a bit again. It should clear the rust from brake components.
Check the Master Brake Fluid
If the car doesn’t move at all, you need to check the master brake cylinder fluid. The master cylinder shouldn’t be full to the brim because there should be some space for the brake fluid to return. Also, check the brake fluid hose for signs of damage or brittleness. If the hose is damaged, you should replace it.
Check the Hand Brake and Replace It If Needed
Then, check the handbrake cable if your car has any. The handbrake cable is located at the rear end of the car. If it is rusty or damaged, you should replace the cable.
Check the Caliper Pistons and Replace Them
If the car still doesn’t move, chances are the problem is with the caliper pistons or slide pins. First of all, use a C-clamp to remove sticking slide pins. If the pistons are seized, you should remove the caliper and push the brake pedal. It will make the piston protrude, and you can replace it with a new one (Our Pick).
How to Prevent Brakes from Locking Up While Parked?
When parking your car for a long time, you need to follow these tips to prevent the brakes from locking up.
- Always park the vehicle in a garage. It will prevent the brake components from catching excess moisture.
- Turn the engine on at least once in one or two weeks. After idling it for some time, you should drive the car back and forth slightly. It will prevent brake components from sticking together.
- Monitor the brake fluid level regularly. And change the fluid when it is dirty or contaminated.
Frequently Asked Questions (FAQs)
Check answers to some frequently asked questions about brakes locking up.
Should I clean rust on brake discs with lubes?
No, you shouldn’t. Applying lubes to the brake discs will reduce friction between the brake pads and discs.
Can I drive with partially locked brakes?
Though it is possible to drive a bit, we don’t recommend driving with locked-up brakes. It will further damage the components.
Does driving with seized brakes affect the rotor?
Yes. If the brakes are locked and you continue to drive, the rotor disc will be extremely hot. As a result, the disc can warp.
Parking cars for a long time are common in winter. When you do this, brake components catch rust or corrosion. Damaged caliper pistons or slide pins can also cause the same problem.
If the brakes lock up while parked, you should identify the reason first. Then, take the necessary steps to solve the problem and get the car rolling again. We have also provided preventive measures so that you can keep your car brakes from getting locked up.