Air is removed from the brake system by bleeding the brake pedal, which requires an assistant.
If it is necessary to bleed the entire system, it is removed separately from each cylinder. This is necessary if air gets into all cylinders. If only one wheel cylinder was replaced or repaired, it is usually sufficient to bleed the corresponding brake cylinder.
Air removal sequence:
- 1. Brake caliper or wheel cylinder rear right;
- 2. Brake caliper or wheel cylinder rear left;
- 3. Front right brake caliper;
- 4. Front left brake caliper.
Remove the boot (arrow) from the brake cylinder air bleed valve. Clean the valve, put a clean hose on it - lower the other end of the hose into a container half filled with brake fluid.
The assistant "pumps" the brake pedal until pressure is created in the system. This is felt by the increased resistance when pressing the pedals.
Once sufficient pressure has been created, press the pedal all the way down and hold it in this position.
Open the valve about half a turn. Collect the flowing liquid in a vessel. Make sure that the end of the hose is always in the vessel below the liquid level.
As soon as the liquid pressure drops, close the valve.
Repeat pumping the brake pedal until pressure is created. Press the pedal all the way down and hold it in this position. Open the valve until the pressure drops, then close it.
Repeat the process of removing air from one cylinder until there are no more air bubbles in the liquid flowing into the vessel.
After removing the air, remove the hose and put the dust cover on the valve.
Remove air from other cylinders in the same way.
Caution: During the bleeding process, monitor the fluid level in the expansion tank from time to time. The fluid level should not drop too low, otherwise air will be sucked in through the tank. Top up with new brake fluid only!
After removing the air, add brake fluid to the expansion tank up to the MAX mark.