How to bleed brake lines

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Normally you don’t need to bleed the brakes after simply replacing the brake pads or shoes. The exception is if while changing the brakes somehow you let air into the brake lines (like if the brake hose detaches from the brake assembly) – in that case you would need to bleed them. Many people also suggest that you should periodically (once every few years) bleed your brakes to help get new, clean fluid into the system.

Let me preface this post by saying that I have bled the brakes on my 1998 Nissan Maxima (now deceased due to a falling tree), but I have not yet bled the brakes on my 2001 Toyota 4Runner during the two years that I’ve had it. Nevertheless, the instructions below are specific to the 4Runner because someone emailed me recently asking for instructions on how to do this.

I think the best way to bleed your brakes is how the Toyota repair manual describes it. Note that the following are taken directly from the repair manual, so if you run into problems let me know and I’ll add your tips and observations to this write-up.

WARNING: Proceed with these instructions at your own risk! There is always risk in performing your own vehicle repairs. Always do your research before starting and be wary of the completeness and accuracy of online tutorials.

Setting Things Up

See in the first picture below how they attach vinyl tubing from the bleeder plug into a container that will catch the brake fluid that will be expelled from the system. Make sure that the tube goes to the bottom of the container – that way it will be immersed in the brake fluid and you won’t accidentally get air pulled back into the brake lines. You bleed one brake at a time, so you only need one container to do this.

Expelling brake fluid and air

Vinyl tube and container for catching brake fluid (image taken from Toyota's repair manual).

Now look at the following three pictures to see where the bleeder plugs are on the front and rear brakes.

Location of Front Brake Plug

Front bleeder plug

The front disc brake bleeder plug (image taken from Toyota's repair manual).

Location of Rear Brake Plug

Rear bleeder plug

The rear drum brake bleeder plug (image on the right taken from Toyota's repair manual). Click to enlarge.

Brake Bleeding Instructions

Now that you see where things are located, follow the steps that Toyota gives (with my own comments added in parentheses):

Bleed Brake Line

  1. Connect the vinyl tube to the brake caliper. (They’re talking about the bleeder plug – and remove the cap from the plug first.)
  2. Depress the brake pedal several times, then loosen the bleeder plug with the pedal held down. (This is where it’s handy to have your buddy help out – one person to do the brake pedal and the other person to loosen and tighten the plug.)
  3. At the point when fluid stops coming out, tighten the bleeder plug, then release the brake pedal. (Note the order – tighten the plug before having your friend release the brake pedal. Also make sure that you have plenty of brake fluid in the reservoir under the hood before doing this so that you don’t make it go empty which will cause a lot of extra work and headache.)
  4. Repeat (2) and (3) until all the air in the fluid has been bled out. (Once again, each time make sure that there is enough fluid in the reservoir before each repetition).
  5. Repeat the above procedure to bleed the brake line for each wheel.

After you’re done you need to check the fluid in the reservoir. Once again, follow Toyota’s instructions:

Check Fluid Level in Reservoir

  1. With the ignition switch OFF, depress the brake pedal more than 40 times.
    • HINT: When a pressure in power supply system is released, reaction force become heave and stroke becomes shorter. (They’re just saying that each time you press the brake pedal it will get more and more difficult to depress it.)
  2. Remove the reservoir cap. Add brake fluid up to the “MAX” line.

Like I mentioned before, let me know if this works well for you or if you run into any hiccups. If it worked out OK then I’ll take some better pictures, describe it better, and put the write-up on my blog.

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This entry was posted in Auto Repair / Maintenance, Automotive, Brakes and tagged , , , , , , . Bookmark the permalink.

6 Responses to How to bleed brake lines

  1. paul says:

    Hi Mike,

    Thanks for the great write-up. I had a stupid question. Are you draining the brake fluid reservoir BEFORE you begin bleeding at each wheel? In other words, when are you adding the new brake fluid into the reservoir? After you bleed the first wheel? (you state to bleed it until no more fluid comes out, but you also state to make sure the reservoir doesn’t empty, so I’m a bit confused). Also, is there an order that must be followed when bleeding the brakes? Ie, which wheel first?

    Thanks again,
    paul

    • Paul,

      I was also a bit confused by those instructions that come out of Toyota’s repair manual. It doesn’t make sense does it? You would expect that if you kept the brake pedal pressed then the fluid would keep coming out of the line until the reservoir was empty (which would be a really, really bad thing to do). Just a guess – but perhaps Toyota included a feature where it won’t drain the reservoir all the way???

      I would suggest that you have your friend press on the brake pedal, and then while the fluid is coming out (don’t wait for it to stop), go ahead and tighten the plug. After tightening the plug, have your friend release the brake pedal, and then put more fluid in the reservoir so that it is full again before you go to the next wheel. I would also suggest bleeding each wheel at least twice before moving to the next wheel.

      You should be OK doing the wheels in any order, especially if your vehicle has traction control (which usually means that each wheel’s brake lines are independent from each other).

  2. When your brakes are not as responsive as they used to be or when the pedal sinks low to the floor, you probably have a leak in your brake system. This could mean that the brake fluid is leaking or that there is an air leak in the brake hose. If there is a puddle underneath your car while it is parked, it is a sign of a leakage.

  3. Angie says:

    When bleeding the rear drum brakes, should I have the e-brake engaged, or does it make any difference?

    • Yes, it’s definitely a good idea to engage the e-brake. The e-brake doesn’t use any brake fluid, so it is a good safety measure to help ensure the vehicle doesn’t start rolling away.

  4. Shauncfranks1124@gmail.com says:

    Hey, I was needing to know the sequence of bleeding the brakes.?

    DF, PF,DR,PR or PR, DR,PF,DF?

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