How To Bleed Your Car's Brakes

Bleeding your brakes will get new ones working or fix existing brakes that have a spongy pedal feel. It can also help improve their response time and decrease stopping distances on the road.

Unlike other car fluids, brake fluid doesn’t have a set interval to change. It should only be checked in response to problems.

What Is Brake Bleeding?

Brake bleeding is the process of purging air bubbles from the brake line. In hydraulic brake systems, brake lines are filled with brake fluid. When you apply pressure to your brake pedal inside the car, the incompressible fluid presses against the brake elements. This causes the brakes to apply.

If air gets into the line, then some of the braking energy is lost by compressing the air instead. If this happens, or if you’ve just installed new brakes, bleeding will make sure the air is out and that the fluid is working properly.

Brake Bleeding Methods

There are many methods of bleeding brakes. As long as the air is expelled from the brake line, they all work just fine. Trying to bleed your brakes with just one person is not as easy, but there are methods out there for it. Speed bleeders can help you do it alone.

Vacuum Method

This method uses a vacuum pump or handheld vacuum gun to move air and liquid through the system. Sometimes air can enter the lines, so this method is not always recommended.

Pressure Method

This is one of the most common and effective methods for one-person situations. By covering the master cylinder reservoir and adding pressure, the fluid is pumped out. The downsides are that set-up can take a while and you’ll need a pressure bleeder.

Reverse Method

This method is often regarded as the most effective. It sends fluid into the system instead of taking it out. By doing so, it pushes air bubbles out through the master cylinder reservoir. However, the brake system must be flushed prior to bleeding, which adds time and effort.

Gravity Method

This is the easiest method for one person, but it’s probably the least effective. It relies on gravity to slowly force the fluid out of each brake. Unfortunately, air bubbles frequently remain in the system, and this method is not good for cars with ABS.

Pump and Hold Method

The pump and hold method is one of the most popular since it’s effective and doesn’t require a lot of special equipment. The caveat is that it’s necessary to have a second person to help. Due to its simplicity, it’s the method we’ll demonstrate in the video and steps below.

How to Bleed Your Brakes: Step-by-Step Pump and Hold Method

Before starting, establish where the master cylinder on your vehicle is and figure out which brakes are the farthest from it. You’ll want to work in order from farthest to closest (unless your owner’s manual recommends otherwise).

Top off the brake fluid in your master cylinder reservoir before starting. Throughout the process, carefully monitor the amount of fluid to ensure you won’t run out. It’s always better to have more on hand than you think you might need, just in case. Be sure to use brake fluid that’s recommended by your owner’s manual.

In addition to an extra set of hands, there are a few tools that you’ll need in order to properly bleed your brakes. One of these “tools” is a container for your brake fluid, but this can be as simple as an old soda bottle with a length of hose.

Required Tools

• Jack Stands or a Lift
• Set of Wrenches
• Brake Fluid
• Container for Brake Fluid

Step 1: Lift Car

Set your car up safely by putting it on jack stands or a car lift.

Step 2: Remove Wheels and Tires

Set them to the side. It’s possible to bleed your brakes without removing the wheels, but it’s less of a hassle if you take them off before starting.

Step 3: Unscrew Bleeder Screw

Unscrew the first caliper bleeding screw on the brake farthest from the master cylinder (one of the rear brakes).

Step 4: Attach Drain Container

Attach your container with a hose to the bleed valve.

Step 5: Pump Brake Pedal to Floor

Have your buddy pump the brake pedal until it reaches the floor. About three to five slow pumps should be enough to feel firm resistance. Then, have them press steadily all the way down. When it falls to the floor, the person pumping should call out “floor” to let the other person know.

Step 6: Put Bleeder Screw Back On

Once your buddy calls out “floor”. Immediately retighten the bleeder screw.

Step 7: Repeat Steps 5-6 Until Pedal Is Firm

If the pedal doesn’t feel normal, repeat the bleeding process again. After about three to four cycles, the brake pedal should feel firm.

Tech Tip: Check the master cylinder’s brake fluid level in between each brake line, to make sure it hasn’t run dry.

Step 8: Repeat Steps 3-7 For Next Brake in Sequence

Continue until all four brakes are bled.

Tech Tip: Some front brakes have multiple bleeder valves so check both.

Step 9: Test Brake Pedal Feel

After bleeding all four brakes, check the pedal feel to make sure it’s normal. Have your buddy apply the pedal fully and then immediately release it. Keep an eye on the master cylinder reservoir. If there’s a significant disturbance from air bubbles, you’ll want to repeat the process or check the troubleshooting section below. A mild disturbance is normal and indicates the system is good to go.

Step 10: Top Off Master Cylinder

Ensure that your master cylinder is topped off with the appropriate amount of brake fluid.

Step 11: Reinstall Wheels and Tires

Bolt the wheels and tires back to the same location.

Troubleshooting Brake Problems

If you’ve just replaced your brakes and bled them properly, finding out that you still have a spongy pedal feel is frustrating. These are some potential problems you might experience after bleeding your brakes or installing new lines. An issue with the brake pedal feel is often caused by air in the lines, but there can be multiple causes.

Brake Pedal Is Low and/or Spongy

Check Master Cylinder Fluid Level

If the master cylinder brake fluid got too low during the bleeding process, it may cause a spongy pedal. Repeat the bleeding process and top off the master cylinder whenever necessary.

Ensure You Bled Brakes in the Correct Order

Failing to start with the brake farthest from the master cylinder can cause pedal issues. Repeat the bleeding process in the correct brake order.

Brake Pedal Gets Stuck or Is Slow to Rise

Check to Make Sure Master Cylinder Is Not Worn or Defective

A worn master cylinder can cause a loss of hydraulic pressure. This can be checked by putting an inverted flare plug into each master cylinder outlet. If the brake pedal is high and feels normal, the master cylinder is likely not the issue.

However, if it sinks, feels spongy, or fades, the master cylinder is the most likely culprit. Check to see if air has gotten into the master cylinder if the pedal feels spongy. An immediately sinking pedal may simply mean that one of the master cylinder’s pistons is stuck.

On the other hand, constant pressure on the brake pedal that results in a gradual sink could be the sign of a larger issue. If the master cylinder was dropped, damaged, or is worn-out, it should be replaced.

Sources: How to Bleed Your Brakes, Car and Driver | 5 Ways to Bleed Your Brakes: Get the Air Out, Hagerty | Why Are My Brakes Spongy?, Wagner | Brake Shop: Brake Bleeding Tips, Motor