Some car maintenance tasks are more widely known and understood than others. For instance, most people know what it means to get an oil change, but few will know what it means to bleed a car’s brakes.
Do you know what it means to bleed your brakes and how to do it?
Bleeding a car’s brakes means removing any air trapped in the brake’s hydraulic parts, like the brake lines. Air typically gets in there when you replace brake parts or when brake parts are too worn out. You can learn how to bleed brakes by yourself, but it’s a challenging process that’s best left to professionals.
In any case, this article will help you understand the entire brake-bleeding process. First, we’ll look at what the process entails and why it matters. Then, we’ll look at the typical steps involved in bleeding brakes.
Let’s see what it’s all about.
What Does Bleed Your Brakes Mean?
If you’ve never heard about bleeding brakes, don't worry! It's actually a routine maintenance task for the hydraulic brakes on your car. To 'bleed' them means to remove any air trapped inside the hydraulics. Naturally, the process will also result in expelling some brake fluid.
How Does Air Get into Your Brake System?
Air enters your braking system in several ways. The most common situation is when you get new brake callipers or brake lines installed. If the installer forgets to bleed the brakes after installing those parts, the air will remain in your brakes indefinitely until you bleed them.
Taking too long to replace worn-out parts, like brake pads or damaged brake lines, can also cause the same problem. Besides undermining your car’s ability to stop, worn-out brake parts can also provide air with an easy way to seep into your brake system.
How to Tell if You Need to Bleed Your Brakes
The most unmistakable sign that you need to spend some time bleeding brakes is when you notice that the brake pedal feels ‘soft’ or ‘squishy’ when you press down on it.
It’s the trapped air in your brake’s hydraulics that causes this. Take note that under normal conditions, this situation never happens. Brake fluid does not compress, so when you press down on your brake pedals, it will create a firm and immediate response on the other end (meaning, your brakes will respond as they should).
Suppose you press down on a brake pedal with air in the system, and the trapped air compresses very easily. You’ll feel something squishy because you’re compressing air rather than creating a response on the other end of the brake system.
Do You Need to Bleed All Four Brakes?
No, when bleeding brakes, you don't necessarily have to do it for all four brakes. That's especially true if your car has independent brake lines that aren't connected.
However, if a mechanic has replaced parts on at least one of your wheels, it’s often a good idea and good standard practice to bleed all four brakes.
You could think of it as a form of preventative maintenance. Sure, it might not satisfy an immediate need. However, you might as well do it while you’re down there working on your brakes anyway. Plus, you could be preventing problems (and headaches) that are just around the corner.
DIY: How to Bleed Your Brakes
If you’re wondering how to bleed brakes by yourself, you must first understand one thing: Yes, you could spend a day doing it yourself at home. However, bleeding brakes DIY is a complex and labour-intensive process, so please consider getting a qualified mechanic to do it for you.
In any case, this is what the process might look like:
- Behind each of the brakes on your car is a small nozzle called a brake bleeder screw. You might need to jack your vehicle up to gain access to these nozzles.
- Using specialised ‘bleeder’ wrenches are needed to unthread the bleeder screw on each brake. If they’re too tight, you could use something like WD40 to help loosen them up. During this step, it's critical not to break any of those bleeder screws.
- Take a flexible hose and place one end over the bleeder screw. The other end should be in a jar or bottle that you’ll use to collect anything that comes out.
- A second person needs to pump your brake pedal a few times slowly. That will help pressurise any air stuck in your brakes and bleed it out into the jar or bottle.
- After pumping the pedal a few times and keeping it down, loosen the bleeder screw. The air will come out of the flexible hose, along with a little bit of the brake fluid.
- While the brake pedal is still down, tighten the bleeder screw to seal the brake’s hydraulic system again.
- Only when the bleeder screw is tightened can your helper release the brake pedal.
- Repeat this process as many times as needed.
Should You Bleed Your Brakes Yourself or Refer to a Pro?
As you can see, even from the simplified explanation above, bleeding brakes involves several steps and can only be done quickly with the help of a second person. So, while it is possible to do it all yourself, it’s also essential to ask yourself whether it’s worth the hassle to do it yourself.
A more efficient way of getting the job done would be to hand it off to a qualified professional, like the mechanics at your trusted workshop. Sure, it might cost you a little bit of money, but you can rest easy knowing that they’ve mastered this task.
Plus, they’d have the workforce and the tools needed to get the job done. So, if you ask me, I’d recommend getting them to bleed your brakes for you.
To discover more car care tips like how to bleed brakes by yourself, check out the blog at CarpartAU. The blog is continually updated with plenty of helpful articles to make you a more knowledgeable car owner!
By Ray Hasbollah