How to judge whether there is air after the brake oil is changed?

Start the vehicle, then step on the brake pedal hard, and finally there is a phenomenon of stepping on the bottom. In addition, it is normal to step on the brakes after the vehicle starts and step on a few brake pedals. When you release the brake pedal for a few minutes, it is normal to step on the brake pedal a few times. This means that there is air in the pipeline of your brake system. The most obvious feeling is that the brakes are soft and hard to use.

What should I do if the brake oil air cannot be discharged cleanly?

Brake oil is incompressible and air is compressible, so if there is air in the oil circuit of the brake system, the feeling of stepping on the brake is completely different, and there will be a feeling of gas compression and rebound. The air in the oil circuit will affect the transmission of braking force and weaken the braking force. The way to exhaust is to have an exhaust port at the end of the brake oil pipe of each wheel, but the operation is complicated and it needs to be exhausted in a professional repair shop.

Why does the brake pipe enter the air?

Air intake in the brake is mainly generated when the brake is released. When the master cylinder returns and the slave cylinder does not return, a certain vacuum will be generated in the pipeline. If the rubber ring of your slave cylinder is not well sealed (it may not leak oil at this time), air will enter a little, which will increase over time, thus causing the symptoms of soft brakes.