Air from the brake system is removed by pumping the brake pedal, which requires an assistant.
Attention: The work steps on vehicles equipped and not equipped with ABS are identical. At service stations, a special installation is used to remove air, connected to a tank with brake fluid. If this unit is connected to an ABS-equipped vehicle, additional air must be bled by depressing the brake pedal as described below.
If you want to remove air from the entire system, the air is removed separately from each cylinder. This is necessary when air enters all cylinders. If only one wheel cylinder has been replaced or repaired, it is usually sufficient to bleed the corresponding brake cylinder.
Bleeding sequence: 1. Brake caliper or wheel cylinder rear right, 2. Brake caliper or wheel cylinder rear left, 3. Brake caliper front right, 4. Brake caliper front left.
Remove boot from brake cylinder bleed valve. Clean the valve, put a clean hose on it, lower the other end of the hose into a vessel half filled with brake fluid.
The vessel must be at least 30 cm above the vent valve. This prevents air from entering through the threads of the bleed valve.
Assistant "pump up" brake pedal to pressurize the system. This is felt by the increased resistance when you press the pedal.
When sufficient pressure is generated, press the pedal all the way down and keep your foot on the pedals.
Open the valve about half a turn. Collect the escaping liquid in a container. Make sure that the end of the hose is always below the liquid level in the vessel.
Release the brake pedal and press it about 12 times until it stops (pump). In this case, the pedal is easy to press. Brake fluid flows out through the valve into the vessel.
Keep the pedal depressed and have an assistant close the valve.
Repeat the process of removing air from one cylinder until air bubbles disappear from the liquid flowing into the vessel.
After removing the air, remove the hose and put the boot on the valve.
In the same way to remove air from other cylinders.
Attention: In the process of bleeding from time to time, observe the liquid level in the expansion tank. The liquid level must not fall too low, otherwise air will be sucked through the tank. Top up with new brake fluid!
After removing the air, add brake fluid to the expansion tank up to the MAX mark.