Do you have to bleed the car brakes to fix them? Or have you changed your brake pads recently and feel like a sponge when you brake? Sometimes it happens that the brake fluid level inside the master cylinder drops too much, and this can cause air bubbles to form inside the tubes, reducing the effectiveness of the brakes. Removing the air will restore strength to the hydraulic brakes. Here is a tutorial on how to bleed your car's brakes thoroughly.
Steps
Step 1. Remove the master cylinder reservoir cap
Typically the tank is light in color and has a black cap.
Step 2. Remove the old liquid
Use a pipette to remove as much liquid as you can.
Step 3. Clean the tank
After removing the liquid, remove any residue from inside the tank using a clean cloth. Do not drop the liquid on painted surfaces or the paint will come off right away.
Step 4. Fill the master cylinder with fresh liquid
Put the cap back on the master cylinder reservoir.
Step 5. Press the brake pedal several times (15 or more)
Step 6. Loosen the purge valves
Use a bolt-sized socket wrench, loosen the valves but leave them closed. A little oil sprayed on the bolts the day before will help.
Step 7. Attach a tube to the bleed screw
Use a plastic tube, such as those used for aquariums, and push one end over the brake bleed bolt.
Put the other end inside a bottle or other container with some new brake fluid inside. In this way you will avoid air being sucked into the cylinder
Step 8. Put a piece of wood or something else under the brake pedal
This will prevent the pedal from going down completely while bleeding the brakes.
Step 9. Refill the master cylinder reservoir
Remove the tank cap and fill it with new fluid.
Step 10. Replace the fuel cap
Step 11. Have someone sitting down to help you hold the brake pedal down
Have it tell you when the pedal is down to the maximum.
Attention: you don't need too much force, just press normally, as if you were to stop at a Stop.
Step 12. Begin with the right rear wheel, turn the bleed screw to the left a quarter turn
The old liquid and the air will end up inside the bottle. As soon as the liquid stops, close the purge valve.
Attention: Remind your helper that the brake pedal he is pressing will go all the way down as soon as you turn the screw a quarter. This is perfectly normal.
Step 13. Tell your helper to take his foot off the pedal which will then come back up
Step 14. Repeat the process until you see clear liquid coming out of the tube
Every five times the brake pedal goes down, remember to fill the master cylinder with fresh fluid. Never let the tank empty too much or air will be sucked into the cylinder.
Step 15. Tighten the bleed screw
Step 16. Repeat steps 12-15 on the left rear wheel
Step 17. Repeat steps 12-15 on the right front wheel
Step 18. Repeat steps 12-15 on the left front wheel
Step 19. Finished
The brakes have been thoroughly bled.
Step 20. Never use an oil that is not suitable for your type of car
Advice
- Always start with the wheel furthest from the master cylinder, usually the rear right. Then switch to rear left, front right and front left.
- DO NOT DO IT YOURSELF, the air can be sucked into the purge valve threads.
- If you are not able, then get expert help or take the machine to the workshop.
- Put a small tube at the end of the purge tap. Dip the other end in a little brake fluid, loosen the tap and press the brake pedal, making sure you always have the master cylinder full.
- Bleed screws can be hard to loosen. Use a wrench of the right size to avoid the risk of stripping them.
- For ABS brakes, a scanner may be required to check the pump and valves.
- Brake bleeding kits are sold in specialized stores. They don't cost much and are a great help.
- Some car models have what is called the “Purge Sequence” due to the various valves and systems used. Ask an expert before you get to work - better not risk damaging the brakes.
Warnings
- Brake fluid can ruin your car's paint! Be careful not to spill it.
- Always use the brake fluid recommended by your car manufacturer. Remember that using a different fluid (such as motor oil) can also cause brake breakage, a much more serious problem and much more expensive to repair.
- Brake fluid is dangerous. Avoid contact with eyes and avoid spreading it where you keep the car. If you can, try to collect it for recycling.
