Does your brake pedal feel spongy?
Does it take longer than usual to stop your car?
Over time, brake fluid can lose its moisture resistance. This loss causes air bubbles to develop inside the brake fluid, reducing performance.
But don’t worry.
You can fix this with brake bleeding.
In this article, we’ll give you a step-by-step guide on how to bleed brakes and highlight what you need to be aware of when you go about doing it. We’ll also cover some FAQs, including the different ways to bleed brakes and when bleeding brakes is not the solution to fixing your car brakes.
This Article Contains:
- How to Bleed Brakes (Step-by-Step)
- 4 FAQs on Bleeding Brakes
Let’s brake in!
How to Bleed Brakes (Step-by-Step)
Bleeding your car brakes requires the right technical know-how.
If you’re unsure, it’s best to call a certified mechanic who can perform the brake service for you.
But if you wish to do it yourself, here are the steps to bleed brakes:
- Step 1: Get the Right Brake Fluid
- Step 2: Mount the Car and Remove the Tires
- Step 3: Loosen the Bleeder Screw
- Step 4: Check the Brake Fluid Level
- Step 5: Cover the Screw Opening with Tubing
- Step 6: Get an Assistant to Engage the Brake Pedal
- Step 7: Repeat on Each Brake
- Step 8: Observe the Master Cylinder Reservoir
Note: We’ve covered the two-person manual method here, but there are other methods to bleed brakes.
However, before we dive into these steps, there are a few precautions to observe.
Precautions for a Brake Bleed:
- Never work on the brakes right after a drive. Brake lines and the brake fluid in them can be very hot.
- Always wear latex gloves while dealing with brake fluid, as it can be carcinogenic.
- Don’t let your brake fluid come in contact with the brake pads or brake rotor. It can lubricate the brake pads and decrease brake efficiency.
- If you spot a brake line leak, ask an auto repair mechanic to fix it first.
- Never reuse old brake fluid. The old fluid contains impurities that can corrode critical parts of your brake system.
- Clean up spills quickly, as brake fluid can eat away your car’s paint.
Now, let’s dive into how to bleed brakes:
Step 1: Get the Right Brake Fluid
The most common fluid is DOT 3, but you should always consult the owner’s manual to get only the specific brake fluid type your vehicle needs.
Good-quality brake fluid isn’t expensive, and you can easily find it at an auto parts store. You may require two or three 12-ounce cans of new fluid to bleed your brake system.
Step 2: Mount the Car and Remove the Tires
Jack up your vehicle on level, solid ground (preferably a garage floor or driveway).
- Place four jack stands at the jacking points shown in your owner’s manual.
- Get a tire iron to remove the lug nuts from your tires.
- Remove the tires and wheels to expose each brake caliper assembly or brake drum.
Step 3: Loosen the Bleeder Screw
Locate each of the four caliper bleeder screws (also called a bleeder valve or caliper bleed screw). You’ll typically find the bleeder screw at the bottom of the brake caliper assembly in a disc brake.
The size and location of a hydraulic brake bleeder valve may vary according to the make and model of your vehicle.
Here’s what you do next:
- Use a box wrench to loosen the bleeder bolt gently. If it resists, don’t twist the wrench too hard.
- Spray the bleeder bolt with penetrating oil and let it soak for 30 minutes. Then, attempt to unscrew it again.
- Once you’ve loosened each bleed screw, place them back again.
You’ll bleed one brake at a time, so every other caliper bleed screw should be closed to prevent air bubble entries into the brake system.
Note: If you snap off or strip a bleeder bolt, stop immediately and call for professional help.
Step 4: Check the Brake Fluid Level
While bleeding brakes, ensure that the brake fluid reservoir stays full at all times.
To do that:
- Lift your car’s hood and locate the brake fluid reservoir.
- Open the master cylinder cap and add fresh fluid if the brake fluid level is lower than the maximum mark. Use only the recommended brake fluid here.
- Keep the master cylinder cap unscrewed but still in place to prevent further air bubbles if the fluid level falls.
Step 5: Cover the Screw Opening with Tubing
Fit one end of clear plastic tubing (¼-inch in diameter) over the first bleeder screw.
You should start with the most distant brake (passenger rear wheel) from the master cylinder, but some cars require a different order. Check that in your owner’s manual or ask your dealer’s service department.
Now, put the other end of the plastic tubing into a disposable bottle containing some clean brake fluid. This measure will prevent air from being sucked back into the brake caliper, wheel cylinder, or brake master cylinder.
Step 6: Get an Assistant to Engage the Brake Pedal
Ensure that your car’s engine stays off while you bleed brakes.
Here’s how you should bleed the brake:
- Ask your assistant to pump the brake pedal several times and then hold the pedal halfway to the floor. If pushed too far, it can drive the secondary piston of the master cylinder across sediments or deposits that can damage piston seals and cause leaks.
Tip: Place a small block of wood underneath the brake pedal to prevent pushing the pedal more than halfway to the floor.
- Next, have your assistant yell “Pressure” when the pedal is down.
- Use the brake bleeder wrench to open the bleeder valve. The hydraulic brake will force trapped air and old brake fluid out of the brake line into the jar.
- When the pedal nears the floor (and touches the wooden block), the assistant should yell, “Down.”
- Immediately close the bleeder valve.
- Ask them to release the pedal and wait for them to say, “Up.”
- Repeat this process several times until no more air bubbles come out with the fluid.
Step 7: Repeat On Each Brake
After you’ve bled your first brake successfully, repeat Step 6 for the remaining brakes.
In most cars, a brake bleeder sequence starts with the passenger rear wheel, the driver rear wheel, the passenger front, and finally, the driver front. However, always follow your owner’s manual for the correct sequence.
Also, check the fluid level in the cylinder reservoir after working on each brake bleed. Top it up with clean brake fluid if necessary.
Once done, securely close each bleed valve and fill the cylinder reservoir with fresh brake fluid.
Next, reinstall the wheels and lower your vehicle to the ground.
Step 8: Observe The Master Cylinder Reservoir
Ask your partner to press the brake pedal firmly and then release it abruptly.
Observe the motion of the fluid in the brake fluid reservoir. A slight agitation in the brake fluid indicates that you’ve done the job right.
However, if you notice a significant fluid eruption, the brake system still has some air bubbles. In that case, you‘ll have to repeat the brake bleeding process.
Let’s go over some questions on bleeding brakes next.
4 FAQs on Bleeding Brakes
Here are answers to common questions you might have about the bleeding process:
1. What are the Other Ways to Bleed Car Brakes?
Other brake bleeding methods include:
- Pressure Bleeding: A pressure bleeder regulates the brake fluid pressure in the master cylinder reservoir and pushes fresh brake fluid through a hose.
- Vacuum Bleeding: Requires a specialized vacuum pump to remove the old brake fluid by attaching the pump’s suction end to the bleeder valve.
- Reverse Bleeding: The brake system is bled by forcing the trapped air up and out of the cylinder reservoir. This method is ideal for ABS brakes.
- Gravity Bleeding: Through gravity bleeding, air bubbles are removed by introducing new brake fluid into the brake system while the old fluid is drained through a plastic hose.
2. When Do I Need to Bleed My Brakes?
A hydraulic brake system works by applying hydraulic pressure as liquid can’t be compressed. However, when air bubbles enter a brake line, and you push the brake pedal, it only compresses the air with minimal force reaching the brake pads.
When that happens, you get spongy brakes, and you’ll have to bleed them out.
Here’re the other situations when a brake repair requires bleeding your brakes:
- When it takes longer than usual to stop your vehicle
- Leaking in a brake line
- Worn-out brake pads
- If you’ve used the brake too much and for too long
- If you’ve changed any of the brake system components like a brake line, caliper pistons, master cylinder, etc.
- As a part of car maintenance
3. When is a Brake Bleed Not the Solution?
Certain brake issues aren’t linked to trapped air bubbles in the brake system.
- A firm brake pedal feel, yet the ABS isn’t working. The problem could be with the ABS module.
- If brakes make noise, the issue could be the brake rotor or brake pad wear.
- If brakes tend to lock and the brake pedal doesn’t return to the neutral position quickly.
- If your ebrake isn’t working efficiently. The issue could be related to your brake lever, i.e., the brake lever cable.
4. Is a Brake Fluid Flush Better Than Bleeding Brakes?
Well, it depends.
A brake fluid flush involves draining all the old, dirty fluid out of your brake system. In contrast, a brake bleed involves removing troublesome air bubbles from your brake fluid.
If the brake fluid in your brake system hasn’t been changed in a while and has become old, a brake fluid flush is the better option.
If the brake fluid in your system is relatively new, but you’re having braking problems from air bubbles, a brake bleed will be much more helpful.
Bleeding your car brakes involves several steps, and it’s crucial to do this brake repair right.
While you could follow our guide to bleed brakes yourself, it’s best to leave this brake service to a professional, such as AutoNation Mobile Service.
AutoNation Mobile Service is a convenient mobile auto repair and maintenance solution offering competitive, upfront pricing.
Our expert mechanics can bleed your car brakes right in your driveway and take care of all your automotive maintenance needs.
Fill out this form for an accurate cost estimate for bleeding brakes or any other brake repair!