Brake Fluid Leak (Causes & Solutions)

Are you concerned that your car has a brake fluid leak? Does your car take longer to slow down than usual? Or do you barely feel resistance as the brake pedal sinks to the ground when you depress it? Are you noticing a strange, yellowish fluid puddle under your car? Worry no more because you’ve come to the right place.

The brake warning light could indicate a brake fluid leak, also, a puddle of brake fluid, the brake pedal losing firmness or going down to the floor, and poor stopping performance can also indicate a brake fluid leak.

This article explains how to identify brake fluid leaks, the causes of these leaks, and the most effective way to fix brake fluid leaks.

Let’s begin!

What Is Brake Fluid?

Brake Fluid Leak

The brake fluid refers to the hydraulic fluid used in your vehicle’s brake system.

When the car’s brake pedal is pressed, the brake fluid serves as a channel to transfer pressure to the braking mechanism of each tire.

Why is a fluid used?

A fluid cannot be compressed, and the applied pressure is evenly dispersed throughout the fluid.

As a result, the brake pedal simultaneously applies equal force to the four tires. The brake fluid’s hydraulic pressure can be affected by air bubbles, which will alter how your car brakes react, so there should be no air in the brake line.

Consider it in this way:

It somewhat resembles water inside a straw. When you blow through one end of a straw filled with water, the water flows evenly together. However, if the straw has air bubbles, the pressure distribution is broken, and the water no longer moves evenly.

So, what happens when there’s a brake fluid leak?

A leak reduces the amount of fluid in your brake line and lets air enter the brake system, so your brakes lose pressure. This decreases hydraulic brake pressure, then causes issues with stopping your car.

Als0 Read: Low Brake Fluid Symptoms (+ How to Fix)

Common Causes Of Brake Fluid Leaks

Brake Fluid Leak

Some very common causes of a brake fluid leak that your technician can identify are listed below.

1. Damaged Brake Master Cylinder Reservoir

Plastic is typically used to make a master cylinder reservoir, and this material may become brittle when exposed to heat. This eventually leads to a crack, which will cause the brake fluid to leak out and then move down the rear of the car engine.

2. Worn Out Brake Pads, Shoes, Rotors, And Drums

Rotors, brake pads, drums, and brake shoes can also be worn with regular use. When this occurs, the wheel cylinder or caliper pistons hyperextend, causing the seals contained in the piston to break and fluid to leak.

3. Failed Piston Seal

Components of a brake such as a disc brake caliper, drum brake wheel cylinder, or master cylinder all require a piston to function.

A piston is a movable component that is activated by the brake fluid. The piston contains seals that aid in fluid containment, and constant wear and tear can damage these seals, leading to leaking brake fluid.

4. Damaged or Loose Bleeder Valve

Brake drums or calipers each have bleeder screws or (bleeder valves) used to “bleed brakes,” which release air from the brake lines. A damaged or loose bleeder valve can result in brake fluid leaks.

5. Damaged Brake Lines or Brake Hose

The brake hoses and lines are made to withstand almost all weather and road conditions. However, they are vulnerable to corrosion, tears, and pitting over time.

A brake fluid leak can be caused by damaged brake line fittings, broken brake lines, or a rip in the vehicle’s brake hose.

Also Read: How Much Does Brake Line Replacement Cost?

6. Faulty ABS Module

High-pressure brake fluid is transported and stored by some components of your brakes’ ABS pump. Unfortunately, the seals on the ABS brake reservoir can wear out over time, which can cause brake fluid leaks.

By now, you or a competent mechanic ought to have identified the cause of your leaking brake fluid.

5 Common Brake Fluid Leak Symptoms

Brake Fluid Leak

1. Puddle of Brake Fluid

It is probably a brake fluid leak if drops of fluid or a little puddle can be noticed on or near the car wheels. If you have a brake line leak or a leaking brake master cylinder, there will be brake fluid beneath your vehicle, and it will be slightly more challenging to identify whether the fluid is brake fluid, motor oil, or transmission fluid.

Brand-new brake fluids have a pale yellow color or could even be clear, and it gradually darkens over time. It feels very much like oil but even slicker, and it has a rotten smell that’s similar to that of fish oil. It is fairly simple to confirm whether or not the fluid underneath the car is brake fluid due to its properties.

For further verification, check to be sure the brake fluid reservoir is still full. If it is not, you probably have leaking brake fluid.

2. Brake Warning Light On

This is usually the first indication a driver would notice related to brake problems because a caution light illuminated on the instrument cluster can be easily seen.

Although it might not necessarily imply that you have a brake fluid leak, as earlier mentioned, most brake issues occur due to insufficient brake fluid, so it can be considered an early signal.

3. Brake Pedal Goes Down to Floor

This usually happens with the brake pedal has a squishy or soft feeling. Problems with your master cylinder or a serious brake fluid leak will result in what some refer to as “brake pedal sink. ” Simply put, this indicates that the brake fluid isn’t enough in the brake lines for your brakes to properly function.

Driving a car without working brakes is extremely dangerous, so if you observe this before you begin to drive, don’t attempt to do so.

If you encounter this when driving, force your vehicle to slow down immediately by gradually deploying your emergency brake or downshifting gears, then safely leave the road. Don’t drive the vehicle until the problem is resolved.

4. Brake Pedal Feels Squishy

The brakes should engage quickly when your brake pedal, which should be firm, is pushed down to stop or slow down your car. In contrast, if your brake pedal is soft, squishy, spongy, or mushy, then air is probably trapped in the brake lines.

Brake lines are usually filled with fluid to properly function (this is why we “bleed brakes”). So if you need to stop suddenly and your brakes aren’t working properly because of a leak, it could have major consequences because your brake lines will be exposed to air.

5. Poor Stopping Performance

Although there are several causes of poor stopping performance, such as problems with the brake pads, calipers, rotors, and more, it’s also possible that you have a brake fluid leak.

Most people first notice only one out of the symptoms mentioned earlier, but if it feels like something is wrong with how your vehicle brakes, you should check the brake fluid reservoir as soon as possible. You probably have a brake fluid leak if this reservoir isn’t filled up.

Regardless of your symptoms, you shouldn’t drive your car until it has been examined and repaired. Faulty brakes are among the most critical car issues that can be experienced and can be life-threatening.

Although it is possible to identify and repair a leaking brake fluid yourself, unless you are certain that you know how to do so, you should contact a technician.

Also Read: Is Brake Fluid Flammable? (Why You Should Be Careful With Them)

How to Diagnose a Brake Fluid Leak

Brake Fluid Leak

Brake Master Cylinder Leak

A fast visual examination of your master cylinder must first be carried out, as it is the simplest. Then, just inspect the state of your brake master cylinder region to determine whether fluid is visible outside it.

Brake Line Leak

In this case, you will need to visually examine beneath the car chassis to determine if the brake fluid is on the floor. The estimated location of the leak will be confirmed if this is so.

If there’s a fluid leak, it is advisable to spread some newspaper beneath the car to stop the fluid from spreading. Even better, there are garage floor mats made specifically for this use. They’re the best method to contain any fluid leak from your vehicle, including brake fluid leaks.

To verify the leak’s location, you should get in your vehicle and pump your brake pedal so that any leftover brake fluid will be forced out. After doing so, you can go under the vehicle again to identify the exact location of the leak. Finally, you could replace or repair your brake line when the leak has been found.

Brake Caliper Leak (or Rear Drum Cylinder)

Check the Rear Drum Cylinder or Brake Caliper: Opening each of the tires to check for leaks at each of the calipers is necessary for this step. If you are inspecting your rear brake with the brake drum, the drum should first be opened to inspect the rear drum cylinder in your brake drum.

Also Read: How Much Brake Fluid Do I Need?

Brake Fluid Leak Repair Costs

Brake fluid leaks can be repaired at an estimated cost of about $150 to $1,000. Although that is a wide range, there are many different reasons why brake fluid leaks can occur.

For instance, replacing your brake line can cost between $150 and $200, whereas replacing your booster may cost between $600 and $800.

No single cause is noticeably more prevalent than the others, complicating the situation further. For example, you might have rusted brake lines more regularly if you drive in a region with a lot of salt covering the road or along the coast where a lot of salt is in the atmosphere.

At the same time, other drivers may discover that their master cylinder would need a replacement more frequently.

Finally, because there are easier jobs to do than others, the labor costs might or might not be ruled out. For instance, if your brake line needs to be replaced and an OEM replacement can’t be found, a repair shop might have to manufacture it.

Even though you may have the required knowledge, you most certainly lack the appropriate tools to do this.

Check out this video for tips on how to fix a brake fluid leak yourself

Frequently Asked Questions – Brake Fluid Leak

Can you drive with a brake fluid leak?

Brake fluid activates the brake systems found in modern vehicles. It is thus imperative that your car has a sufficient amount of brake fluid to ensure your safety and your family’s safety. A brake fluid leak is the most prevalent cause of complete brake failure, so you should never drive a car with brake fluid leaks.

How much does it cost to fix a brake fluid leak?

Brake master cylinder leaks often cost between $450 and $550. Brake line leaks can cost about $150 to $200. Costs for a leaking brake caliper range from $550 to $750. Usually, a leaking rear drum cylinder can cost about 150 to 200 dollars.

What happens if your car is leaking brake fluid?

What happens when brake fluid leaks occur? First, your vehicle loses brake pressure because a leak reduces the amount of fluid in your brake line and allows air into the brake system. The decreased hydraulic brake pressure then causes issues in stopping the car.

What are the common brake fluid leak symptoms?

The brake fluid generally leaves a slick residue on the fingers when touched and has a light yellow to brownish color. Brake fluid is probably leaking if the leak can be traced back to your master cylinder beneath your vehicle’s center, your brake lines, or the drums or rotors close to the wheels.

How serious is a brake fluid leak?

Brake fluid, which is essential for your vehicle to operate safely, is made to help transfer the force and movement produced when your brake pedal is pressed down. Brake fluid leaks can result in issues in stopping the vehicle, caused by a reduction in brake pressure.

What causes you to lose brake fluid?

A brake fluid leak can happen due to simple things, such as typical wear and tear or the driver running into something while driving on the road. Leaks can usually be identified when a residue is left beneath a parked vehicle or by inspecting the brake fluid reservoir under the car hood.

Will brakes still work without fluid?

The calipers push the brake pads against the brake rotors, putting friction and pressure on the car wheels and bringing them to a stop. Your car could be unable to finish this process effectively if the brake fluid level is not adequate.

Where does brake fluid usually leak from?

A brake fluid leak is usually caused by problems with the brake line, master cylinder, bleeder valve, ABS module, rotor, pistons, drum, or the general brake components, so checking what component the leak is under could indicate the source of the brake fluid leak.

Can I just top up brake fluid?

If the brake fluid level is under the ‘low’ marker, the fluid should be added to increase the amount of brake fluid. If the level remains low when you check it soon after, you probably have a brake system leak. This could also be due to worn-out brake pads because when they are worn, the brake calipers would have a further distance to cover, and more fluid is drawn into the brake system.

What does low brake fluid sound like?

If strange sounds are noticed when braking, it may result from issues with the brake system, such as insufficient brake fluid. Grinding or scraping noises are common sounds that can be heard. Also, a burning smell after hard braking may mean your brake fluid has burned out.

How long should brake fluid last?

Almost all drivers discover that their brake fluid needs to be changed at least once in four or five years.

Conclusion – Brake Fluid Leak

Several factors can cause brake fluid leaks, such as damage to the brake components and general wear. Rusting, pitting, and other conditions that affect the calipers and other brake parts can also cause leaks. If your dashboard brake fluid indicator is lit and your reservoir is low despite you topping up your fluid, there’s a high chance your hydraulic brake system is compromised.

We hope this post was of help to you. Please feel free to check out our other blog articles if you want to get more tips for fixing and preventing car troubles!

Leave a Comment