In a 10,000-mile drive, you’ll hit the brakes an estimated 60,000 to 70,000 times. However, brake fluid is widely regarded as the most neglected fluid in your vehicle, despite its importance to your safety. Replacing brake fluid is an easy procedure that you can do yourself. Here are the tools you need: brake fluid specific to your vehicle, brake exhaust pump, collection bottle, gloves, wipes and safety glasses. I’m Larry Kosilla, a professional detailer and trainer for the past 15 years, but when it comes to what’s behind the scenes, I’m a student.Follow me as experts teach me how to diagnose, repair and modify cars Auto Blog Wrench.

How often should brake fluid be changed?

It depends on the type of vehicle you drive, your driving style and the climate you are in. The latter can be a very important factor affecting brake fluid. There are different types of brake fluid with different boiling points, so be sure to replace the old fluid of the same grade, or change to the fluid that suits your driving purpose (for example, some fluids are better for track work). Check your owner’s manual for more information about your vehicle. In our case we are using DOT 4 which can be easily found in any auto parts store.

Two ways to deflate the brakes

As far as I understand, there are two main types of brake bleed techniques. The two-person method, known as “pedal bleed,” is when one person hits the brakes while the other bleeds the brake lines at the same time. But today, I’m going to learn a quicker and easier one-man method called “pressure bleed.” The purpose of the bleed brake line is to squeeze or push out the old fluid without letting any air back into the system. This can be a big problem if air does get into the system.

How Brakes Work and Why Bleeding Brakes Makes a Difference

The brakes are hydraulic, which means that when you press the brake pedal, the brake fluid, which is not easily compressible at this pressure, transmits the force of the pedal through the brake lines to the calipers, which squeeze the rotors and stop the car. If air enters the system through a poor brake leak process or a leaking brake line, the force of the pedal will compress the air instead of the fluid. That’s why the brakes sometimes felt squishy and didn’t stop like they should.

How to get started

Before opening the brake fluid cap, clean the surrounding area to avoid any dirt accidentally entering the system. Keep in mind that brake fluid will damage the paint on contact, so wear gloves and goggles, and of course cover the paint and avoid drips. Now, unscrew the lid and use a turkey masher to remove most of the old liquid from the master tank. Do not remove all liquids. Leaving some liquid in the master tank will help prevent air bubbles from entering the system.

Next, use a tool called a power bleeder, which uses pressurized brake fluid to drain air and old fluid from the brake lines. Simply pour your specified brake fluid into the pressure tank, install the nut onto the brake reservoir, and use the hand pump to pressurize the system to about 15 pounds on the gauge. With the brake system pressurized, it is time to move to the corner of the vehicle that is furthest from the master cylinder. Connect the brake bleed collection bottle to the caliper pilot valve located on or near the caliper.

Now you always start with the caliper furthest from the master cylinder. In our case it was the passenger side rear. Temporary bottles can be made at home, but for $10 to $12 online, the bottles are airtight, have magnets, and have a safety thread, and are worth the price. Depending on the type of wrench you use, it may need to be in place before connecting the hose. With the hose firmly connected, open the vent valve until you see the old brake fluid being pushed out of the system and into your collection bottle.

Note clear liquid and air and repeat

Watch the brake fluid change from old brown to new or clearer, indicating that the lines are full of new fluid. Then, close the valve, no need to overtighten here, just comfortable. Make sure to check your power bleeder for enough pressure and brake fluid to continue. You will most likely need to pump it up to add up to 15 lbs. Make sure to check your power bleeder after every corner, you want to avoid running out of brake fluid during the bleed process as this will inadvertently add air to your system. Repeat this process for the rear of the driver’s side, then the front of the passenger’s side, and finally the front of the driver’s side closest to the master cylinder, in this order. Keep in mind that some high-performance calipers have multiple bleed valves attached, so contact the manufacturer for recommended bleed sequences or suggested tips. When you’ve done all four corners, test your pedals before driving to make sure it feels firm.

If not, repeat the process until a firm pedal returns. Then, slowly release pressure from the power bleeder and unscrew the bleeder cap, top up the master cylinder reservoir with brake fluid and replace the cap. Remember that brake fluid contains polyethylene glycol, which is present in some paint solvents and is extremely corrosive. Be sure to remove your gloves before getting in the car or touching the paint, as you may have some old brake fluid on it, which could turn a quick brake flush into a full repaint. Once the project is complete, we have all the used fluids we need to dispose of now. Make sure you do it right. Check with your local auto parts store to see if they recycle or if they can direct you to a local collection facility. For more videos on auto repair, visit autoblog.com/wrench. I’m Larry Kosilla from ammonyc.com, and as always, thanks for watching.

watch all our Auto Blog Wrench Video for more tips on how to diagnose, repair and modify your car from professional groomer Larry Kosilla.While you’re at it, check out Larry’s other car cleaning and maintenance video series Auto Blog Details!