Expert Advice | How To Bleed Brakes | 5 Methods To Know

Here are five possible ways on how to bleed brakes. The first one is a two-person method; you need a friend or a family member to assist you. The four other methods are one-person. Whatever the method you’ll use, the process itself is not rocket science.
How to bleed brakes? All what you need to know

I spent several hours researching the best methods and put together simple and clear steps. I aim to cut through the jargon and help you make the right decisions for your car care and maintenance.

You can see these five methods as specific choices in the middle of the bleed brakes process. The starting point is the preparation phase and the end is the final check phase.

Before You Start

Your reference must be your car service manual

Please note that all cars are different. This article should be used as a general guide. The content below is not a substitute for your car service manual.

Throughout the entire process, your reference must be your car service manual. If you are not sure you can properly perform any of the steps or methods below, stop and consult a professional technician. Of course, you can still read the whole article to expand your knowledge and learn more about this topic.

Brake fluid is very caustic. So, avoid drips or spills and immediately remove and clean any touched area. [1]

Understanding The Process

The core steps are the same

In a nutshell, bleeding the brakes consists of releasing the air trapped within the lines of the braking system by forcing new brake fluid through the braking system. The goal is to purge the trapped air and replace the used fluid. [2]

In this article, we’ll explain five different methods to bleed brakes. No matter which method you’ll use, once you’re done with the preparation phase, the core steps are the same:

  • Starting with the brake furthest away from the master cylinder.
  • Filling the brake fluid reservoir with fresh brake fluid till the MAX marking.
  • Cleaning off the area around the bleeder screw, so there is no chance of dirt contaminating the area you’re working with.
  • Purging trapped air and used fluid in each brake by loosening and tightening its bleeder screw.
  • Repeat the above step until air bubbles are no longer visible and the fluid turns clear.
  • Ensuring the master cylinder has a fresh brake fluid during the whole process and is topped off before opening the bleeder screws.
  • Moving to the next brake, always starting with the most distant from the master cylinder.

Preparation

Some preparation first

To bleed brakes, you have first to do some preparation. You will need these elements:

  • Box-end wrench to manipulate the bleeder screws. The standard size of 5/16 in. x 3/8 in and an offset head design usually works best.
  • Brake fluid. There are several different types, and they don’t mix well. You have to consult your car manual and check which type of brake fluid your vehicle requires.
  • Disposable bottle for capturing old fluid.
  • Clear tubing. Usually, a diameter of ¼ inch will work. The tubing must be long enough to put one end into the disposable bottle and the other end tightly over the end of the bleeder screw of the brake you’ll be bleeding.
  • Safety glasses and gloves.
  • Brake cleaner.
  • Shop rags or towels.

It’s highly recommended to lift your car and remove all wheels. It’s easier to reach bleeder screws if you jack up your vehicle. Bleeder screws, little nozzles, are always located at the top of the brake calipers and are usually covered with a rubber cap. You can refer to your car manual for the appropriate lifting and support techniques. As a safety precaution, use a jack stand as well. [3]

#1: The Traditional Two-Person Method

Traditional two-person method

One person stays close to the disc brake caliper to manipulate the bleeder screw. Let’s assume it’s you.

The other person sits in the driver’s seat to manipulate the brake pedal. Let’s assume it’s your assistant.

As you guessed, this method requires good communication and timing between you and your assistant.

  • Tell your assistant to depress the pedal several times, then hold it down. 
  • Your assistant should give you a clear confirmation once the pedal has been fully depressed.
  • Open the bleeder screw a quarter to half turn briefly and let the fluid fill the attached hose.
  • Close the bleeder screw without over-tightening it.
  • Tell your assistant to release the brake pedal only once you give him a clear confirmation that the bleeder is closed.
  • Repeat the bleeding until air bubbles are no longer visible and the fluid turns clear.

#2: The Simplest One-Person Method

Simplest one-person method
  • Attach the hose to the bleeder screw. 
  • Stick the bottle in plain view.
  • Open up the bleeder screw.
  • As you watch the air and old brake fluid flow out of the lines, keep an eye on the bottle. It may seem empty one minute and overflowing the next.
  • Close the bleeder screw

#3: Hand-Held Vacuum Pump Method

Hand-held vacuum pump method

This is a one-person method to bleed brakes. Yes, you need to buy a hand-held vacuum pump kit which comes with the necessary accessories.

The method is quite easy. Indeed, the kit, a vacuum-pulled brake bleeder, creates a vacuum that sucks the old fluid out. The main steps are as follow:

  • Attach the bleeder screw adapter, hoses, and catch container.
  • Pump the vacuum several times (10 to 15 times should be enough).
  • Loosen the bleeder screw about a 1/2 turn until brake fluid draws out.
  • Close the bleeder screw to stop extraction.
  • Repeat the bleeding until air bubbles are no longer visible and the fluid turns clear.

#4: Pressure-Operated Venturi Method

This method is similar to the previous one, the vacuum-pulled brake bleeder. The main difference is that a pressure-operated venturi brake bleeder uses compressed air and a venturi —fancy jargon for the cone-shaped tube memorizing Giovanni Battista Venturi who discovered the venturi effect. [4]

Therefore, this kind of brake bleeder increases the flow velocity of the brake fluid, resulting in a fast and more efficient brake bleeding process.

#5: Pressure Tank Method

Pressure tank method

The pressure tank is another one-person easy method to bleed brakes. Some consider this method the best of brake bleeders and they accept no alternatives as it is very effective when they want to push every air molecule and rotten brake fluid out of the lines. [5]

The mains steps are as follow:

  • Attach the bleeder kit to the brake fluid reservoir.
  • Pressurize the tank to adequate pressure. 
  • Fill the bleeder with up to 2 quarts of fresh brake fluid.
  • Pressurize it again to the proper pressure. Higher pressures may damage your hydraulic system.
  • Loosen the bleeder screw.
  • Bleed until the fluid is free of bubbles and runs clear.
  • Tighten the bleeder screw

Final Phase

Final phase, it’s time for the final check

After bleeding all the brakes, you’re almost done. It’s time for the final check.

  • Clean and wipe any spilled brake fluid off your calipers.
  • Tighten each bleeder screw
  • Cover bleeder screws with the rubber caps if removed earlier.
  • Put the wheels back on your car, tighten the lug nuts to the right torque and re-install any hubcaps or wheel covers.
  • Lower your car.
  • Double-check that the brake fluid reservoir is at the MAX fill line.
  • Start your car and keep it in the park or neutral position.  Depress your brake pedal. After a couple of pumps, the pedal should feel firm and nice and no longer spongy when you press it.
  • Use caution and road test your car. Perform several low-speed stops to confirm the brakes are functioning properly.

Congratulations! Now, your brakes are bled. It’s time to enjoy rides with a reliable stopping system.

If your pedal brake still feels soft and spongy, don’t panic. Such a case isn’t unusual. Just try bleeding the brakes one more time and repeat the whole process. It will not take as long as it seems to be.

The Bottom Line

Over time, brake fluid begins to absorb small amounts of water which causes a dangerous driving condition: the air bubbles make your brake pedal feel soft and spongy, reducing your brake system performance.

The solution is to bleed your brakes. As described and explained throughout this article, you can choose one of the five methods on how to bleed brakes.

Do not hesitate to let a professional bleed the brakes for you if you feel not comfortable with the process.

Do you know that you also need to check your brake pads? Check out our list of 6 signs when to replace brake pads.