How to judge that there is air in the brake fluid, and how does one exhaust the brake air

I believe that many of my friends’ cars have been out of warranty and replacedBrake FluidIt must be familiar to you all. However, some of my friends worry that an error occurred during replacement, causing air to enter the brake hose, which would affect the braking effect of the car. So how do we judge that there is air in the brake fluid? How can one exhaust the brake air if the air is really in the air?

If air enters the brake hose, when we step on the brake, we will feel that the brake pedal will be very soft, and we will feel that the brake is stable only when we step on it to the end. Secondly, if you step on the first foot and feel very soft, but after a few minutes you step on the first foot again, the first foot is very low, and after a few more feet, the normal condition will be restored, indicating that the brake hose is indeed There is air, it needs to be discharged in time, otherwise it will directly affect the future use.

But one person cannot exhaust the brake air, because one person needs to step on the brake continuously, and then press the brake pedal firmly, and then another person loosens the bleed screw on the brake cylinder, and The air is exhausted. You can’t just loosen the brake and screw the screw, because stepping on the brake itself is to squeeze the air to the end of the sub-cylinder, which is near your oil drain hole. If you loosen it at this time, the air cannot be discharged. NS. In general, it cannot be done by one person unless the machine is used to change the brake oil, but the machine does not need to be drained at all to change the oil.