Bleeding Brakes 101: A Beginner's Guide On How To Bleed Brake Lines

Dealing with a spongy brake pedal? Or maybe you just finished a brake line replacement and need to get air out of the system? The good news is that bleeding your brakes is a DIY auto repair you can absolutely tackle in your own garage.

 

We're going to walk you through the three most popular ways to bleed your car's brakes, from the old-school two-person method to the slick one-person tools.

Before You Start: Brake Bleeding Tips

No matter which method you pick for bleeding your brake lines, these 3 steps are essential. Get these right, and the rest is easy.

1. Safety first: Get the car safely in the air. Jack it up and always use jack stands. You'll need to pull the wheels off to get to the bleeder screw at each caliper or drum.
2. Bleeding order: Always, always start at the wheel furthest from the master cylinder and work your way closer. For most cars, that order is:
   • Right Rear (Furthest)
   • Left Rear
   • Right Front
   • Left Front (Closest)
3. Never let the master run dry: This is the #1 rule. Keep the master cylinder reservoir topped up with fresh, clean brake fluid. If that level drops too low, you'll suck in a ton of air and have to start the entire brake bleeding process all over again (and you might even have to bench-bleed the master, which is a huge pain). Check it constantly!

Method 1: The Two-Person Job

This is the classic, reliable way to bleed brakes. Grab a buddy, a clear-ish container, a small piece of tubing, and a wrench that fits your bleeder screw.

• Person 1 (The Pumper): Sits in the driver's seat.
• Person 2 (The Wrench): Mans the bleeder screw.

Here's the process:

1. With the bleeder screw closed, the Pumper slowly presses the brake pedal 3-4 times, then holds it firmly to the floor.
2. Once they're holding, they'll indicate "Holding down!"
3. The Wrench cracks open the bleeder screw. Old fluid and air bubbles will shoot out into your tube. The pedal will start to fall.
4. Before the pedal hits the floor, the Wrench tightens the bleeder screw and yells "Closed!"
5. The Pumper can now release the pedal.
6. Repeat this process until you see a solid, clear stream of brake fluid with no air bubbles.

Check the master cylinder fluid level, top it off, and move to the next wheel.

Method 2: The One-Man (Bottle Bleeder) Method

Don't have a helper? No problem. This is the most common one-person brake bleeding method. You can buy a simple brake bleeder tool (it's just a bottle with a tube and a one-way check valve) or easily make your own.

To make a DIY brake bleeder tool: Grab any small plastic bottle and a short piece of clear tubing that fits snugly on your bleeder screw. Fill the bottle an inch or two with clean brake fluid - just enough to cover the end of the hose. This stops air from getting sucked back in.

Here's the bottle bleeder process:

1. Put your wrench on the bleeder screw.
2. Push the hose over the bleeder, with the other end submerged in the fluid in your bottle.
3. Crack the bleeder screw open (about a quarter-turn).
4. Go to the driver's seat and slowly pump the brake pedal. Push it down, then let it return up. The old fluid and air get pushed into the bottle, and the fluid in your DIY bottle stops air from coming back in on the up-stroke.
5. Repeat this until you see no more bubbles in the clear tube.
6. Tighten the bleeder screw, remove the tool, and move on. (Don't forget to check and top-off the master!)

Method 3: The Power-Up (Vacuum Bleeder) Process

This is the fast way, but you'll need an air compressor. A vacuum brake bleeder uses compressed air to create a vacuum and suck the fluid and air out of the bleeder screw.

1. Hook up the tool to your air compressor.
2. Put your wrench on the bleeder screw and attach the tool's hose.
3. Loosen the bleeder screw.
4. Squeeze the trigger. The vacuum will start pulling fluid and air out of the system.
5. Heads up: This method is notorious for pulling tiny air bubbles past the threads of the bleeder screw, making it look like you still have air in the brake line. Don't panic. Just let it run until you've pulled a good amount of fluid through and the stream looks mostly solid.
6. Tighten the bleeder, remove the hose, and you're set.

Final Brake Line Bleeding Checks

No matter what method you used, your last two steps are always the same:

1. Do one final top-off of the master cylinder reservoir to the "FULL" line.
2. Put your wheels back on, torque your lug nuts, and before you drive anywhere, pump the brake pedal. It should feel firm and solid, not soft.

If your pedal still feels soft or spongy, you may have a stubborn air bubble. Don't worry, just run through the bleeding sequence one more time. It'll come out. Additionally, be certain you torque your lug nuts the right way - stay tuned for our next post where we walk you through how to torque your wheels the right way, every time.

A solid, safe brake system starts with solid, reliable lines. If you're bleeding your brakes because you're installing a brake line replacement, make sure you're using the best. LinesToGo offers a huge selection of high-quality brake lines, fuel lines, engine oil cooler lines, and rack and pinion lines, and more.

Give our experts a call at (855) 781-5992 or contact us online to order your replacement lines today!