Brake maintenance is one of the most common jobs the home mechanic will undertake. And one of the more common jobs is bleeding air out of the system, a task that you might assume requires two people.
But what if you don’t have a helper nearby? 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 nowhere to be in a hurry? Then you can let gravity do the bleeding for you. This method works for nearly all modern cars, as long as the master cylinder is up high on the firewall, above the level of the wheels.
All you have to do 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 bleed screw and top up the master cylinder.
Repeat on the other rear brake, this time taking a lunch break. Top off the fluid. Then do the passenger-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 bleed screws closed, pump the brake pedal and it should be nice and solid.
Bleeding brakes with a bottle
This technique is nearly as simple as using gravity, but is also much faster, is the bleed bottle. You can make one 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 set-up 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 that's 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 be sucked back into the system. Now, just put the other end of the tube over 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 quickest (and most expensive) way to bleed brakes on your own is by using a vacuum pump. This looks similar to a kid’s squirt gun, but instead of squirting water when you pull the trigger, it sucks in air or fluid. These pumps are typically about $30, but the good news is that the can be used for various other automotive tasks, 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. Just fill up the master cylinder, suck out the old fluid and any air, and close the bleeder. Then move on to the next wheel.
Who needs friends when the right tools will do the job!