How to bleed your brakes effectively

Quick insights

• Bleeding brakes can help maintain optimal brake performance and safety by removing air bubbles that can cause a spongy brake pedal.
• The entire process of bleeding brakes typically takes between 30 minutes to an hour, depending on the vehicle and the technician's experience.
• You should try to bleed your brakes at least once every two years to maintain effective braking performance, with more frequent maintenance required for vehicles in harsh environmental conditions.

Ever felt like your car's brakes are just taking a long, deep breath every time you step on the pedal? It might be time to give your brakes a break. Keeping your brakes well-maintained isn't just about performance; it's about safety. In this article we’ll break down how and why to bleed your brakes.

Why bleeding your brakes is important

Bleeding brakes is an important maintenance task that ensures your vehicle's braking system operates efficiently. Air trapped in the brake lines can lead to a spongy brake pedal, which significantly reduces the driver's control and increases the risk of accidents. By removing these air bubbles, you restore the full function of the braking system, ensuring quick and responsive stops. Regular bleeding also helps maintain the integrity of the brake fluid, which can absorb moisture over time and degrade, further compromising the brake system's effectiveness.

And in case you’re wondering, it's called "bleeding" because it involves releasing fluid from the braking system.

What you need to bleed your brakes

Before you start bleeding your brakes, it's important to gather all necessary tools and materials to ensure a smooth and safe process. Here’s what you’ll need:

• Brake bleeding kit: This includes a bleed screw wrench, clear tubing and a collection bottle. The kit may also come with a hand pump to help force the brake fluid through the lines.
• High-quality brake fluid: Check your vehicle’s manual for the specific type of brake fluid required. You’ll need to make sure you’re using the correct fluid to avoid damage to the system.
• Helper or brake pedal depressor: Bleeding brakes is often a two-person job. It's very helpful to have someone to press the brake pedal while you open and close the bleed valve. If you're doing it alone, a brake pedal depressor can hold the pedal down for you.
• Protective gear: Safety glasses and gloves are very important when bleeding your brakes. Brake fluid is corrosive and can cause irritation or damage if it comes into contact with skin or eyes.
• Wrench set and rags: Some additional tools, like additional wrenches, may be needed for opening the bleed valve. Rags will help clean up any spills promptly, as brake fluid can damage car paint.

Once you have all your tools and materials ready, you can move on to the actual process of bleeding the brakes.

Please note that you may want to check your car's manual or consult with a mechanic before you attempt to bleed your own brakes. Every car's brake system works a bit differently, and the following instructions may not be accurate for every vehicle.

How to bleed your brakes

Now that you have prepared your workspace and gathered all necessary equipment, you can begin the process of bleeding your brakes. This procedure will flush out old brake fluid and any air pockets, ensuring your braking system operates efficiently and safely. By following a systematic approach, you can remove old brake fluid and any trapped air, which are common causes of reduced braking performance.

• Locate the brake bleeder screw: Begin by identifying the bleeder valve on each brake caliper. It's usually a small nipple-like protrusion with a hexagonal top that can be opened with a wrench.
• Set up the bleeding kit: Attach the clear tubing from your bleeding kit to the nipple on the bleeder screw. Ensure the other end of the tube is submerged in the collection bottle to prevent air from re-entering the system.
• Pump and hold the brake pedal: Have your helper pump the brake pedal several times to build up pressure, then hold it down firmly. This action compresses the brake fluid in the lines. If you're working alone, you can use a brake pedal depressor to hold the pedal down. This tool wedges between the seat and the pedal, maintaining pressure while you work on the bleeder valves. Check that the depressor is securely adjusted to prevent any slippage that could release the pedal prematurely, which would interrupt the bleeding process.
• Open and close the bleeder valve: While the pedal is held down, open the bleeder valve to allow the old fluid and air to escape into the collection bottle. Close the valve before the pedal is released to avoid sucking air back into the system.
• Repeat for each wheel: It's important to work on one wheel at a time, moving from the wheel furthest from the master cylinder to the closest. In this way, all lines should be bled properly.
• Check and refill the brake fluid reservoir: The master cylinder reservoir is a container that holds the brake fluid for the entire braking system. It's typically located near the engine and is connected to the brake lines that run to each wheel. As you bleed the brakes and fluid is expelled, the level in this reservoir will drop. It’s important to regularly monitor this reservoir and keep it filled to the appropriate level throughout the brake bleeding process. This can allow for a continuous supply of fluid without introducing air into the system.

After completing these steps for each wheel, you will have successfully bled your brakes, which should result in a firmer brake pedal and more responsive braking. This not only enhances your driving experience but also significantly increases your safety on the road.

How long does it take to bleed brakes?

The entire process of bleeding brakes can take between 30 minutes to an hour depending on the vehicle and the person's experience. Each wheel typically takes about 10 to 15 minutes to properly bleed.

When bleeding brakes, it's important to take your time to make sure all air is removed from the brake lines for optimal performance.

How often should you bleed your brakes?

It is recommended to bleed your brakes at least once every two years to maintain optimal brake function. Vehicles frequently driven in harsh conditions or used for performance driving may require more frequent bleeding.

Always consult your vehicle’s owner manual for specific recommendations regarding brake maintenance.

What to do if brake bleeding doesn't work

Sometimes, despite following all the steps correctly, you might find that the brake bleeding process doesn't resolve the issue of a spongy brake pedal or poor braking performance. This could indicate a more complex problem within the brake system that requires additional troubleshooting.

• Recheck all connections: Ensure that all hoses and connections are secure and that there are no leaks. Even a small leak can allow air to enter the system, which can prevent successful bleeding.
• Verify the bleeding sequence: Different vehicles may require a specific order in which the brakes should be bled, typically starting from the wheel furthest from the brake fluid reservoir. Double-check that you are following the correct sequence for your vehicle.
• Inspect damaged components: Look for signs of wear or damage on the brake lines, calipers and the master cylinder. Worn or damaged parts may fail to seal properly, allowing air to enter the system.
• Consider the brake fluid condition: If the brake fluid is dirty or contaminated, it can cause issues in the hydraulic system. Make sure you are using fresh, high-quality brake fluid that meets your vehicle's specifications.

If after these checks the problem still persists, it may be time to consult a professional mechanic. Complex brake issues, such as a faulty master cylinder or internal leaks, benefit from professional diagnosis and repair. Expert assistance can be helpful and keep your vehicle safe on the road.

The bottom line

Bleeding your brakes is a key maintenance task that helps ensure the safety and reliability of your vehicle's braking system. By following the correct procedures and using the right tools, you can maintain healthy brakes and keep your vehicle driving safely. Remember, if you encounter persistent issues during the bleeding process, seeking professional help is advisable to avoid compromising your vehicle’s safety.