Car Maintenance 101: Bleeding your Brakes (Two-Person Brake Fluid Flushing)

While brake bleeding is a crucial part of auto maintenance, it’s not really something that people like to do. Bleeding your brakes can be an extremely messy affair, plus if you’re the guy (or girl) who gets stuck removing the bleeder screws or brake bleed screws, it requires a lot of contorting just to gain access to the auto parts that you need to remove.

It’s going to be an extremely taxing affair, so if you’re not up to it or if after reading this post, you’re still not sure about what to do, then I suggest you have a professional mechanic assist you while you bleed your brakes.

The Importance of Bleeding Your Brakes

With all that said, you’re probably wondering why you actually have to do this in the first place. When you bleed your brakes, you’re basically removing your old brake fluid that may be contaminated or may have air bubbles. Once air gets into your brake fluid, your braking system’s performance decreases dramatically. This could also result in a “too-soft” braking pedal that heads to your floorboard with the slightest pressure.

So How Does Air Get Into Your Braking System?

Leakage at the fittings where your hoses and lines connect with your master cylinder can introduce air to your braking system. Air can also enter through corrosion on your calipers, brakelines, and wheel cylinders.

What You’ll Need:

  • a willing and helpful assistant
  • transparent, plastic tubing
  • a box wrench
  • a couple of 8 oz. Brake Fluid cans
  • spacer (usually in the form of 1×4 wood)
  • transparent plastic bottle
  • a turkey baster
  • a bunch of clean rags

Why You’ll Need an Assistant:

While you can choose to bleed your brakes alone, bleeding your car’s brakes with an assistant makes the job a lot easier and simpler. When you have an assistant, one of you will have to step on the brake pedal while the other opens the bleeder screws to drain your brake fluid.

Make sure your assistant can hear you while you give out instructions. It’s crucial that the brake pedal is never released while the bleeder is open. If this happens, expect air to enter your braking system immediately.

Where Do You Start?

The sequence of wheels being bled depends on the type of vehicle you have. To make sure you’re doing the right thing, do consult your owner’s manual or even your service manual. Don’t forget to check for specific ABS-procedures and DOT-grade brake fluid suggestions. Keep in mind that the brake fluid you’re going to be using should meet your vehicle’s specifications.

As a general tip, remember that front-wheel drives are usually bled in a diagonal sequence. If you have a rear-wheel drive vehicle, it’s always a good advice to start on the wheel that is farthest from your master cylinder.

Other Reminders Before You Start:

  • Make sure you have the right brake fluid for your vehicle. If you don’t, expect brake failure sometime soon.
  • Try to find goggles to keep your eyes protected, or make sure no brake fluid will enter your eyes. Be extra-careful when catching brake fluid as these things can be incredibly hard to remove.
  • Keep the brake fluid away from your paint, as this fluid can destroy your auto’s paint and polish.
  • Because bleeder bolts can be so hard to remove, make sure you have the right-size box wrench for the job.

How to Bleed Your Brakes:

Step #1: Find out the sequence on which wheel needs to be bled first, second, third and last. If your vehicle is relatively new, then it may have a specific bleeding sequence. DO check with your mechanic first to see if there are specific steps you need to conduct before you actually bleed your brakes.

Step #2: Locate your master cylinder reservoir and remove its cap or top.

Step #3: Use your turkey baster to remove as much dark fluid as you can. Doing so lessens the brake pedal-pumping required to bleed your brakes.

Step #4: Using a clean rag, try to clean as much of the reservoir as you can. When doing this, avoid spilling your brake fluid over your vehicle as this will ruin your vehicle’s paint instantly.

Step #5: Bring out one of your brake fluid cans and fill up your master cylinder. You’re going to be removing the brake fluid and adding some more in a bit, so keep your brake fluid can accessible.

Step #6: Seal the master cylinder reservoir again.

Step #7: Pour a couple of inches of brake fluid onto one of your transparent, plastic bottles. This way, when you bleed your brakes later, no air will be sucked into your brake cylinder.

Step #8: Have your assistant pump your brake pedal several times. After doing so, make sure the brake pedal doesn’t touch the floorboards while you loosen your bleeder bolt. You can do this by inserting your spacer between the brake pedal and the floorboard.

Step #9: While your assistant is doing this, bring out your box wrench and loosen your bleeder. Your box wrench should fit your bleeder bolt. Loosen your bleeder valves, but make sure the entire contraption remains slightly closed.

Step #10: Take your plastic tubing and push one of its ends over your brake bleed bolt. Now insert the other end of your plastic tube inside your bottle.

Step #11: Once again, put more brake fluid into your master cylinder reservoir. Make sure you replace the top of the reservoir.

Step #12: Give your partner the “go signal” to remove the spacer. This time, your assistant will have to depress on the brake pedal steadily and hold it down for a while.

Step #13: Proceed to the wheel that you’re going to be “bleeding” and remove the bleeder. Start by turning the bolt a bit and letting air and old fluid drain into the bottle.

Step #14: When the brake pedal is already touching the floor or if it is as low as it will go, then close the bleeder. Let the fluid drain.

Step #15: When there is no more fluid coming out, close your bleeder and ask your assistant to remove his/her foot from your brake pedal.

Step #16: Continue this process until clear fluid comes out of your bleeder. Make sure that every few times the brake pedal is depressed, you top off your master cylinder reservoir with fresh brake fluid. Don’t forget to replace the top of the reservoir after filling it up and don’t let the brake fluid levels inside your reservoir sink too low or air will enter your master cylinder.

Step #17: When it’s just clear fluid that’s coming out, tighten your bleeder and proceed to the next wheel.

Step #18: Repeat Step #8 – #17 for the next three wheels.

Step #19: Take your vehicle for a test drive and try out your brakes.


3 Responses to Car Maintenance 101: Bleeding your Brakes (Two-Person Brake Fluid Flushing)

  1. Fred Clay says:

    Nice post! It looks like an easy job and also not messy at all (in the picture), yet it’s so important.


  2. autofrankie says:

    Thank you Fred! :)

  3. […] Source: Auto Mechanic | Auto Mechanic Repair and Maintenance Tips […]

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