How to Bleed Car Brakes
Brake fluid is crucial for the braking system of a car. Although it can serve its purpose for years without replacement, the fluid is prone to lose its water-resistance over time. Absorption of water not only affects the car brake fluid but can also lead to the corrosion of brake components. Changing the brake fluid at regular intervals is thus crucial. One of the main steps of changing the brake fluid is bleeding your car brakes.
Here is a detailed guide on how to bleed your car brakes.
Bleeding your Car Brakes – An Overview
Bleeding brakes simply means removing the air in the brakes. Some residual fluid is also expelled. You can do a DIY job to bleed your car brakes. However, before you start the process, it is recommended you consult a professional especially if it is your fist time bleeding the brakes.
Once you are confident you can handle the task, read the following instructions to bleed your car brakes without any further professional help.
Things you will need for bleeding your car brakes
- Box-end wrench
- Brake Fluid (as per your car’ manual)
- Fluid holder and tubing (available at any automotive store)
- A friend for assistance
Steps to Bleed your Car:
- Check your car manual to find out which type of brake fluid you need. There are various types of brake fluids and they may not mix well. Head over to your nearest auto part store to buy the right grade brake fluid.
- Jack up your car on solid, level ground. Support it with the four jack stands by fixing them to the jack points. Check your car’s manual to find them. You will have to climb under the car at times. Therefore, make sure your car is levelled and high above the ground. Now remove the car wheels. Here is a guide on how to use a car jack safely to help you with that.
- Once you remove them, locate the bleeder screws. Loosen the screws gently. If the screws resist, do not put too much pressure. Instead, use penetrating oil and let it stand for half an hour before attempting to loosen again. In case, the screws snap off, stop putting pressure and take the car to a professional.
Once all the screws are loose, tighten them back. Bleed one brake at a time and keep others sealed to prevent any air sucking back in the brake system.
- Locate the master cylinder reservoir using your car manual. Check the brake fluid level and fill it if you see less than the ‘lower’ mark on the reservoir. While you are at it, keep the master cylinder cap in place but do not screw it back.
Always bleed the car brakes in order. In most cases, the brake farthest from the master cylinder bleeds first. However, you should consult the car’s manual to find the right order.
- Take one end of a piece of clear tubing and fit it on the bleeder screw of the brake you will bleed first. Put the other end of the clearing tube in a catch container, which can be an old plastic bottle or can. The tubing should be long enough to let the catch container hang above the bleeder screw’s height. This will prevent the air trapped in the tubing from returning to the calliper.
- Now ask your helper friend to pump the brake pedal for various strokes until there is solid resistance underfoot. Make sure the car engine is turned off during this step. A good idea is to ask the helper to shout ‘pressure’ once the firm pedal is achieved. The pressure on the pedal should be maintained.
- While your friend maintains the pressure on the pedal, open the bleeder screw slightly. This causes the fluid to pass through the clear tube and within the time the pedal starts dropping towards the floor.
- Just when the pedal is about to reach the floor, the helper should shout ‘Floor!’ This is the cue for you to close the bleeder screw quickly. Now check the fluid level in the master cylinder reservoir. Add more brake fluid if required to keep it topped up.
- Continue to repeat steps six to nine for five times at least for one wheel location. The point is to ensure the fluid stream through the clear tubing has no air bubbles.
- Repeat the six to nine steps for the rest of the three brakes in the right sequence.
- Once the car brake bleeding is complete, ask the assistant to put maximum pressure on the pedal followed by a quick release. Observe how the fluid moves in the master cylinder reservoir. If you find substantial fluid eruptions, it means some air bubbles are still in the system. If this happens, repeat the bleeding process to ensure removal of all air. A modest fluid disturbance is an indication of properly bled brakes.
- Now double-check that you have tightened all the bleeder screws. Put sufficient pressure to tighten them but don’t overdo it. The screws must not be damaged.
What is the right order to bleed brakes?
For most vehicles, the car brake bleeding order starts with the passenger’s rear brake. Then comes the driver’s rear and then passenger front. The last one is the driver’s front. However, the right order can be found in the car manual.
Do I bleed brakes with the engine running?
No, bleeding brakes should always be done with the engine off. A running engine will supply a vacuum boost to your car brake system. To bleed all the air from the system properly, there must not be any boost.
Do I need to bleed all four brakes?
Bleeding all four brake lines is a common practice. However, if the brake line is independent, then there is no need to bleed all four4 brakes.
This concludes the guide on how to bleed your car brakes. To ensure your brake system is up to date, you can buy car brake equipment. Car brake bleeding kits are also available in the market. Keep your car running smoothly on the road with these automotive tools for sale.
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