Workshops use a device to remove air, which is attached to the brake fluid expansion tank. The device creates pressure in the hydraulic circuit of the brakes (Max. 2.0 bar).
If the air must be removed from the entire system, then the operation is carried out separately for each wheel brake cylinder. This occurs when air has entered each brake cylinder. In the case when only one caliper or wheel brake cylinder has been replaced or repaired, it is usually sufficient to bleed the air from this cylinder.
The sequence of operations for removing air:
1 - rear right brake caliper, 2 - rear left brake caliper, 3 - front right brake caliper, 4 - front right brake caliper.
Remove the dust cap from the brake cylinder bleed valve. Clean the bleed valve, put a clean hose on it, insert the other end into a vessel half-filled with brake fluid.
Ask an assistant to press the carrion of the brake until pressure appears in the brake system. This is felt by the increasing resistance as the pedal is depressed.
If sufficient pressure is reached, depress the pedal to the stop and hold it with your foot.
Open the bleeder valve on the brake caliper with a wrench about a pop of a turn. Collect escaping brake fluid in a container. At the same time, make sure that the end of the hose in the vessel is constantly below the level of the liquid poured into it.
Close the bleed valve as soon as the brake fluid pressure drops.
Release the brake pedal and repeat the pumping process until the brake fluid pressure rises. Leave the brake pedal depressed, open the bleed valve until the pressure drops, then close the valve.
Repeat the process of removing air from the brake cylinder until air bubbles stop flowing together with the brake fluid that flows into the vessel.
After venting, remove the hose from the valve and put the dust cap on the valve.
Attention: When removing air, observe the liquid level in the compensation tank. The liquid level must not fall too low, otherwise air will be sucked through the expansion tank. Always top up with new brake fluid!
Similarly, bleed the other brake cylinders.
After removing the air, replenish the liquid level in the compensation tank to the MAX uterus. Check rubber seal -1- for damage. Screw on the tank lid.
Attention. Run a security compliance check:
- Are the brake hoses tight?
- Is the brake hose in the holder?
- Are the air bleed valves tight?
- Is there enough fluid in the brake system?
- With the engine running, perform a leak test. To do this, act on the brake pedal with a force of 200 to 300 N for about 10 seconds (from 20 to 30 kg). Do not release the brake pedal. Check all connections for tightness.
After bleeding the brake pedal "fall through" should not. If this happens, repeat the bleeding procedure from the brake system.
Note: Handle brake fluid as special waste.