Besides oil changes, brake jobs are one of the other most common jobs of the home DIY mechanic. There are certain aspects of working on the brakes, however, which require bleeding the air out of the system. Is bleeding brakes necessary? Absolutely, and it typically needs the help of a friend to step on the brake pedal while you loosen and tighten the bleed screw.
But what if you don’t have a helper handy at the time? Here's how to bleed brakes by yourself.
Read on and we’ll go over a handful of techniques that allow a single person, with just two normal length arms, to bleed the system.
Bleeding brakes by gravity
Got plenty of time to kill? Then you might just want to let the force of gravity do the bleeding for you. This method works for nearly all modern cars, and anything as long as the master cylinder is up high on the firewall, above the level of the wheels.
Where do you start when bleeding brakes? All you have to do with this method is fill up the master cylinder reservoir with fresh fluid. Then starting at the wheel farthest from it (typically the right rear), loosen the bleed screw on that brake caliper/cylinder. Go inside and play on your phone for at least an hour. Close the bleeder screw and top off the master cylinder.
Repeat on the other rear brake, this time taking a lunch break. Top off the fluid. Then do the passenger’s side front, then the driver’s side front brake, waiting at least an hour for the fluid to drain and topping off the master cylinder each time. Now, with all the bleeders closed, pump the brake pedal and it should be nice and solid.
Bleeding brakes with a bottle
Nearly as simple as the force of gravity, but much faster, is the bleed bottle. You can make this simple tool yourself from any clean jar or bottle with a lid you happen to have around. You will also need a length of hose that fits over the brake bleeder nipple. Aquarium air tubing works great.
You can buy a setup like the one pictured above, with the added bonus of a magnet to keep the fluid higher than the caliper, for $5 at most auto parts stores.
To make your own, drill a hole in the lid of the jar, just big enough to squeeze the hose through without it falling out. Drill a second tiny air hole in the lid. Pour just enough fluid into the jar to cover the end of the hose - this way no air can get in. Now, just hook the hose to the bleeder, and open it. Top off the master cylinder, then pump the brake pedal a few times. If you check the hose it should be full of fluid with no bubbles. Close the bleeder and repeat at each wheel, making sure to top off the master cylinder each time.
How to bleed brakes with a vacuum pump
The fastest way to bleed brakes without a partner, and also the most expensive, is with a vacuum pump. This handheld pump looks similar to a child’s squirt gun and is actually very similarly built. Instead of squirting water when you pull the trigger, it sucks in air or fluid. These pumps are typically about $30 and can be used for various other automotive tasks as well, such as testing EGR valves.
The quick and easy vacuum method works much like the other two. Instead of forcing air and fluid out of the caliper with the brake pedal, you suck it out with the vacuum pump hooked to what amounts to the bleeder bottle. Fill up master cylinder, suck out the old fluid and any air, and close the bleeder. Then move on to the next wheel.
Now with these tricks, you no longer need a friend, just the right tools.