bleeding the brakes

Bleeding The Brakes – Why It Is Important

Vehicle brakes play a key role in safety. Driving is illegal when your brakes are damaged or unresponsive since you can cause accidents. Regular brake maintenance ensures they keep working well and that you are always safe when hitting high speeds. Bleeding the brakes is part of the maintenance process.

Bleeding brakes remove trapped air from the brake system. The brake hydraulic system opens under pressure allowing air to escape and improving efficiency. Understanding the basic functioning of the braking system helps while bleeding them. When you apply brakes, it will transmit pressure through the brake fluid. The clamping system feels it and engages at the end of the hydraulic system. It attaches to the tire and reduces the vehicle’s speed. This will make the vehicle stop.

After some time, however, the braking will cause air accumulation in the hydraulic braking system. When the connector opens, the air gets in to release the braking fluid. As the fluid releases, air will enter and cause these inefficiencies. It also arises when the braking pads become too worn out. When there is a fluid leak in the system, air will enter. You can check out this guide if your brake fluid is not coming out while bleeding.

Finally, air comes from accumulated heat in the hydraulic system. It is due to aggressive brake usage that heats the braking fluid, and since it is hygroscopic, it will release moisture and cause vapor accumulation. Thus, the air in the hydraulic system needs to be bled out.

When Should You Bleed The Brakes?

Although bleeding the brakes is part of maintenance, it isn’t required often. There are, however, unique circumstances that make it necessary. Once you identify them, you can better maintain your vehicle’s braking system and ensure effectiveness. Here’s what to look out for.

#1. If your brake pads wear out: As highlighted earlier, worn-out brake pads cause hydraulic fluid leakages and thus reduction. As it leaks, it creates room in the vacuum filled with air. It makes the system ineffective, and a need for bleeding arises.

#2. When you replace the drum brake cylinder or the disc brake caliper: The replacement involves disconnecting the brake lines, and in the process, air could get into the braking system. Bleeding is needed to get it out and restore proper brake performance.

#3. After continued hard braking: if you brake hard continuously and for a long time, heat will accumulate in the hydraulic system, and the braking fluid will overheat. You will have to release it through bleeding to restore proper performance.

#4. Any disconnection in the hydraulic braking system: The braking system creates a vacuum within the hydraulics. It ensures proper pressure transmission and better braking. When you replace any component, you have to bleed the braking system to release any trapped air in the process.

How To Bleed The Braking System.

Although bleeding the brakes is technical, you can still do it yourself. Contact your local garage for repairs or assistance if you run into problems. Various considerations help determine the extent of bleeding and the possibility of challenges you will encounter. They include an ABS in your vehicle.

If you have an ABS, bleeding will become significantly challenging compared to vehicles without. This is because air might have entered the ABS modulator, and you need a scanning device to check that out. Some systems can also be bled only with a scan tool. Unlike others, these are challenging since only mechanics have these. However, if your vehicle is a standard model without these, you can bleed it easily.

#1. Opening the Bleeder Screw

This is the first bleeding step where you have to open the valve on each wheel cylinder on the hydraulic braking system. Ensure its components are well-cleaned while at this step.

#2. Releasing the Braking Fluid

You can now have an assistant to help you press on the brake pedal. It will build up the pressure just like while braking. On removing the valves, the braking fluid will drain out. The air previously trapped in the system will be released in the process. You can also connect a master cylinder reservoir to the power bleeder to help drain the fluid.

#3. Adding fresh braking fluid

As you drain the braking fluid, you should simultaneously add a fresh one to prevent air entry. It will take up any space previously occupied by air. It ensures bleeding, the braking system is successful, and works correctly. You can use a master cylinder reservoir to coordinate both actions better.

Precautions To Take While Bleeding

Bleeding the brakes is simple, but thorough consideration should be maintained for best performance. Firstly, raise the vehicle to make bleeding easier and for better coordination. It also builds up pressure easily, making air escape faster. Secondly, you should handle the bleeder screw carefully since the caliper will not work well when damaged.

Finally, handle the brake fluid carefully as it can cause skin irritations. Additionally, ensure you have the right brake fluid that will work well and maintain low temperatures under intense braking. Your driving style should influence your choice of braking fluid, as fast drivers will need more braking force than their slower counterparts.


Bleeding the brakes allows your hydraulic system to work better. If there isn’t any air in the system, you won’t need to press hard on the brakes for the vehicle to stop. The hydraulic braking system maintains and transmits the pressure if you are pressing the brake pedal.

Identify the instances that prompt brake bleeding early on and perform it. Delays can easily damage your braking system and increase wear and tear. You will thus end up needing costly repairs in situations simple bleeding would have alleviated the problems. You can now bleed the brakes, and in case you encounter problems, contact your mechanic.