It’s important to use a brake bleeder to bleed the brakes of a car following a component replacement involving one of the brake lines.
You may also need one when old fluid needs to be flushed.
A spongy feel when applying the brake pedal is often a sure sign that there is air in the brake lines in need of removing.
Bleeding the brakes using a vacuum brake bleeder pump, is the most common and user-friendly approach.
Luckily, it’s a straight forward job, and this article will take through the process of “how to use a brake bleeder”.
Before you Begin
It always pays to consult your vehicle’s manual prior to using a brake bleeder to ensure there are no special instructions to consider.
The job will require brake fluid, and it is highly recommended that brand new, unopened fluid is used.
I will go into the reasons for this later on in the article.
Ensure that the car is parked on an even surface, then raise the car with a sturdy jack and secure it on a jack stand, remove all 4 wheels and tires.
It’s advisable to apply some penetrating oil to the bleeder screws the day before to ensure they turn easily.
This “how to use a brake bleeder” guide requires the following items:
- Hand-held vacuum kit – which should contain pump, empty reservoir/jar, 2ft fuel hose (3/16ths) and connector pieces for the reservoir/jar. You will need a minimum of 2 empty jars.
- New brake fluid – Old brake fluid will have built up moisture and humidity that will affect the performance of brakes over time. Using new fluid is highly recommended for this task.
- Car jack and Jack stand – to raise the car and remove the wheels. Make sure the jack is fit for purpose according to the weight of the vehicle.
- Lug wrench –to adjust the bleeder screw. The size of the screw will vary depending on the car brand.
- Towels – simple shop towels to clean the master cylinder cap and the bleeder screw, preventing the entry of contaminants to the line.
- Owner’s manual/repair manual – consult to ensure the process is compatible with that stated in the vehicle’s manual. It will give some instructions on “how to use a brake bleeder”.
- Penetrating Oil (Optional) – to apply to the bleeder screws to avoid difficulty when turning.
Check out: Best brake bleeding kits
The Steps to Follow
The following steps will now demonstrate “How to use a brake bleeder” with a vacuum bleeder kit:
Remove the cap of the brake master cylinder, ensure that the fluids inside don’t get contaminated with grease or dust.
Top the cylinder up to the MAX line using the new brake fluid. Make sure it never drops below the MIN line as this will introduce air into the system.
Connect all the components of the vacuum kit, with the empty reservoir connected to the fuel hose and the fuel hose ready to connect to the bleeder screw.
To prevent grease and other dirt from contaminating the brake line, thoroughly clean the bleeder screw before connecting the fuel hose.
Loosen the bleeder screw very slightly with the lug wrench, then connect the fuel hose to the bleeder screw, ensuring a tight seal.
Now proceed to press the brake pedal at normal pressure several times to remove the vacuum from the brake booster. Do not start the engine for this process.
Check the level of brake fluid in the master cylinder, top it up the MAX level if necessary.
Now, squeeze the vacuum pump handle 10-15 times to create negative pressure from the fuel hose bleeder screw.
Now give the bleeder screw a half inch turn to open it.
Now, you should see brake fluid flowing into the empty reservoir/jar.
Keep a close eye on the empty jar and keep pumping the vacuum until the fluid is just below the top of the jar.
Now tighten the bleeder screw, replace the jar with a new one and repeat all the steps from 4 through until 9.
By now all the air should have been removed from the lines, and it’s time to move on to the next wheel.
Constantly check the level of the master cylinder reservoir and top up the level with brake fluid to ensure that the level never dips below MIN.
This will introduce air bubbles into the line defeating the very the objective of the task.
Also, check that the bleeding screws on each have been tightened sufficiently after using a brake bleeder.
Pump the brake a few times, then check for leaks.
It is also advisable to start with the rear wheels and clear the longest length of brake line first.
This will help to eliminate trapped bubbles, the closer one gets to the master cylinder.
Also read: Best mechanics creeper seats
Now, to test if the use of a brake bleeder has been successful, apply normal brake pressure to the pedal looking out for the spongy, soggy feeling that was previously there.
If the brakes feel solid the purge has been a success. If not, repeat the process.
A slow, careful test drive around the block will be the final indicator as to the success of the brake bleed.
This article lays out a clear process to demonstrate “how to use a brake bleeder”.
If the user has followed the steps carefully, the vehicle in question should be purring and the brakes be rock solid for whatever the road has in store.
The method described in this article is a one-man job and should take no longer than an hour, however, an assistant to pump the brake pedal when required, is always welcome.
So, rather than handing this straightforward maintenance task over to a garage, get equipped with the correct tools and learn “how to use a brake bleeder”.