Why Is My Brake Pedal Soft? (11 Reasons Why)

You’re driving down the road, cruising along at an excellent speed, when suddenly, your brakes don’t feel as solid as they did before you started. If so, be alarmed.

Brake systems come in different levels of performance and quality, so the experience can vary. In addition, these brake pedals can become spongy as they get worn down over time. That’s why we will enlighten you with all the information you require!

Why Is My Brake Pedal Soft?

When your brake pedal seems soft, you should check if there is air in the system. Contamination of brake fluid may occur, allowing rust and toxins into the vehicle system. In such an event, if you notice a loud squeaking noise coming from your brakes, this may be a sign of a malfunction in your brake lines.

Let’s determine the leading causes of why you encounter spongy brakes while driving!

1. Air On Brake System

In air brakes, compressed air is utilized in place of hydraulic fluid. As a result, air pressure overwhelms the brake system at idle, releasing the brakes.

As well as that, the air is the foe in a hydraulic system because it lowers pressure and renders the operation ineffective.

Otherwise, look for any leaks in your reservoirs, which could indicate a bad connection between them and the master cylinder.

Because of that, if you notice that your brakes are suddenly spongy, there is likely air in the brake lines or reservoir.

2. Faulty Brake Lines

Brake lines are typically held together with clips that fit into holes at each end of the line.

That said, because the brake fluid cannot reach the tire’s braking mechanism when your brake line is damaged, your hydraulic system will not function.

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However, most brake systems include two independent circuits, creating a divided braking system that helps to prevent total brake failure.

Therefore, the brake pedal will feel mushy and may even drop to the floor if braking fluid pressure is lost.

3. Contaminated Brake Fluid

Brake fluid contains additives that help lubricate your brakes, so they operate smoothly and efficiently when pressed on by your foot pads during use.

On the contrary, your brake fluid can become contaminated by dirt or water, which can cause the brakes to be less effective or even fail if not serviced regularly.

Due to this, if any sedimentary deposits on the pistons float around in your reservoir, you need to replace them with new fluid immediately!

Overall, a contaminated system will result in mushy brakes that don’t work correctly and cause trouble for drivers and passengers.

4. Brake Booster Leakage

Brake boosters increase the forces that are sent to the brake master cylinder.

In line with this, the brake fluid transforms the force into hydraulic pressure in the brake lines and engages the brake caliper at each wheel to slow the vehicle.

Further, in the event of a vacuum leakage, it might result in uncontrolled air in the induction system of your engine.

Additionally, you’ll observe a decrease in engine RPM and perhaps an engine stall.

Therefore, if you notice that your brake pedal suddenly feels squishy as usual, check for leaks around your brake booster.

5. Cracked Master Cylinder

Your master cylinder controls pressure to your front and rear calipers, preventing friction between your wheels and the road or other surfaces.

For example, incorrectly placed wheel bearings and misaligned or rusted brake calipers are examples of broken master cylinders.

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In addition, an internal leak in a master cylinder makes it challenging to maintain the required hydraulic pressure.

As a result, a cracked master cylinder will cause your pedal to feel elastic when pressed down, which may result in emergencies like breakdowns along highways.

6. Unreliable Brake Calipers

Unreliable Brake Calipers

Your brake calipers are small pistons that push against your rotors when your vehicle’s parking brake system applies.

However, driving a car on rotors that are worn out is a significant reason why calipers get damaged.

It is when the system’s inability to dissipate frictional heat as it should harm the calipers.

As a result, no pressure is exerted on the line brakes, making your pedal seem spongy and floppy.

7. Erroneous ABS Modulator

If an ABS control module malfunctions, you’ll probably notice it when braking hard. Thus, if your ABS module is acting strangely, your brakes may lock up even during routine braking.

As such, the brakes may exhibit strange behavior, such as intermittent clicking noises.

As an outcome, this component malfunctions can result in squishy brakes since it sends a signal to the ECU to activate the brake system.

8. Misaligned Rear Brake Shoes

If your brake shoes are misaligned, they won’t apply evenly to the rotor and will produce inconsistent braking power.

Further, when the brake pedal is adjusted by pressing the brakes on a vehicle with a rear brake, the rear shoes may not be adequately modified.

Therefore, you may notice this by having to push harder on the brake pedal or may encounter a springy feel when you apply the brakes.

9. Wheel Cylinder Leaks

A leaky wheel cylinder compromises your car’s braking performance.

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As well as that, leakage results from worn rubber piston seals that become brittle with age. Fluid can flow through the pistons due to a damaged piston seal.

For that reason, a leaking wheel cylinder lets air between the brake pads and rotors. However, less friction is created between the two components, leading to mushy brakes.

10. Worn-Out Brake Pads

Pads and rotors should be replaced every 100,000 miles to ensure your vehicle is working correctly.

With that, the common warning signs of worn brake pads are low brake fluid, skidding when coming to a stop, and difficulty stopping quickly.

Generally, you could notice that the brake pedal seems soft upon pulling the car to the other side.

11. Uneven Drum Brakes

Brake rotors can sometimes wear unevenly, leading to a condition known as Disc Thickness Variation (DTV).

That said, DTV can be brought on by various things, including rust, sticking calipers, excessive braking, and sticking calipers.

Undoubtedly, if you see any signs of irregularities on your drum brakes, this could be why your brake pedal feels pappy and rubbery.

To know more, you can also read our posts on why your gas mileage is going down, why your transmission fluid is brown, and why your speedometer is not working.


A soft brake pedal can indicate a severe problem with the brakes of your car that should be addressed immediately.

If you encounter these issues, the most common causes are a brake system with air on it, broken brake lines, and tainted brake fluid.

By all means, look at those brakes. Today’s brake systems are sophisticated equipment and must be maintained regularly!

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