How to Bleed Brakes and Why It's Necessary
For the home DIYers wondering how to bleed brakes, this guide will cover what you need to know. We'll look at what's required, the steps on how to bleed brakes, and how to avoid common mistakes.
How to Bleed Brakes: Key Takeaways
- The goal of bleeding your brakes is to remove air from the brake lines and replace brake fluids.
- Air buildup can cause your pedal to feel softer; bleeding brakes will restore their firmness.
- You should bleed your brakes whenever you work on the braking system.
- The methods on how to bleed brakes are straightforward but vary depending on whether you're working alone or with an assistant.
How to Bleed Brakes: The Tools You'll Need
- Your vehicle's owner's manual or service manual
- A jack and four jack stands
- Replacement brake fluid
- Combination wrench (typically with a 5/16-inch opening)
- Clear, flexible plastic tubing (usually with a 1/4-inch diameter)
- A brake bleeder vacuum pump with built-in fluid reservoir (if working by yourself)
- An assistant who can press the brake pedal (if working with another person)
- An empty plastic bottle or other container
- Work gloves and eye protection
- Flashlight
How to Bleed Brakes: Steps Before You Start
- Get enough brake fluid to fully refill the system: It's better to be able to fully change brake fluid during this process.
- Jack the car and place it on four jack stands: Ensure that the car is balanced on the four jack stands, with each placed under a jack point.1
- Determine the bleeding order: Every car has a specific pattern for how to bleed brakes. Check your owner's manual or service manual and take note of this pattern before you begin.
- Top up the brake fluid reservoir: Bleeding your brakes will involve changing brake fluid, as the bleeding process extracts it from the car. Never let the reservoir go dry! Top it up before and throughout the bleeding process.1
How to Bleed Brakes: By Yourself
Once you've topped up the fluid reservoir, have the wheels off, and have your car safely on jack stands,1 do the following:
- Determine the first brake caliper to bleed.
- Put the end of your wrench on the brake bleeder valve screw.1
- Attach your clear plastic tubing to the brake bleeder valve.1
- Attach the correct end of your brake bleeder vacuum pump to the clear tubing, ensuring a seal has formed.1
- Squeeze the vacuum pump handle until the pressure gauge needle reaches around 15 PSI (specific pressure can vary by car).1
- Use the wrench to open the bleeder valve.1
- Observe the amount of bubbles coming through the tubing.1
- Close the bleeder valve once the flow of bubbles begins to slow down.1
- Check the brake fluid reservoir and top it up as necessary.1
- Repeat steps five to eight until no more bubbles appear in the tubing.1
- Dispose of the brake fluid in the vacuum pump's reservoir.1
- Move on to the next caliper and repeat the previous steps.1
If you're wondering how to change brake fluids by yourself, simply continue to pump fluid even when no more bubbles appear.1 Make sure to top up the reservoir frequently and continue bleeding your brakes until only fresh fluid flows out.1
How to Bleed Brakes: Two Person
If you have someone to help, follow steps one to three of the previous method, and then do the following:
- Put the end of the clear tubing into a disposable container.1
- Keep the car turned off, and have your assistant sit in the driver's seat.1
- Have your assistant pump the brakes until pressure builds and the pedal is firm.1
- Have your assistant shout "pumped" once the pedal is firm.1
- When you hear this cue, use your wrench to open the bleeder valve.1
- Ensure your assistant keeps pressing the pedal.1
- Have your assistant shout "it's down" right before the brake pedal hits the floor.1
- When you hear this cue, use your wrench to close the bleeder valve.1
- Check and top up the brake fluid reservoir.
- Repeat steps three to eight until no more bubbles appear in the tubing.1
- Dispose of the fluid in the container.1
- Move on to the next caliper and repeat the previous steps.1
As with changing pads to deal with brakes squeaking, communication between you and your assistant is key.
Common Mistakes When Bleeding Brakes
Like using performance brake pads with low-grade rotors, mistakes can be made during this job.
- Not testing the brake pedal before driving again: With either method, you should test the brake pedal's firmness after you close all the bleeder valves but before you put the wheels back on.
- Letting the brake fluid reservoir go dry: If there's no fluid in the reservoir, air can freely enter the brake lines and leave you with more bubbles to remove.
- Tightening the bleeder valves too much or not enough: Using too much force can destroy the valves; if they're too loose, air could enter the system again.
- Bleeding the brakes in the wrong order: Always follow the official manufacturer guidelines.
For more information on how to bleed brakes or how to change your brake pads, the BrakeTimeUSA team is here to help.
Frequently Asked Questions
What is the proper way to bleed brakes?
There are two proper ways to bleed brakes. Properly bleeding brakes on your own involves attaching a vacuum pump and a clear line to the brake bleeder valve, creating a vacuum, opening the valve to let air and fluid flow out, closing the valve, and then repeating the process. The other way is similar, but a helper will pump the brake pedal to push the air and fluid out.
Can you bleed your brakes by yourself?
Yes, you can bleed brakes by yourself by using a vacuum pump tool (often called a "brake bleeder vacuum pump" or "brake bleeder tool"). The steps will be mostly the same as if you were bleeding the brakes with two people, but rather than having an assistant pump the brakes to push out fluid and air, you'll pump the vacuum pump tool to suck up air and fluid.
Do you pump brakes when bleeding brakes?
If you're bleeding brakes using the two-person method, you will need to pump the brakes. Using this method, your friend will need to pump the brakes until noticeable pressure has built up, and then you will need to open the brake bleeder valve to let air out of the brake lines. Ensure you're familiar with all required steps before attempting this.
1This web page is not intended to replace this service that is to be performed at an official dealership. It is your sole responsibility for any injuries and damages incurred as a result of performing such actions contained in this webpage. Contact us for complete details.
