抄来的：

Start your car and press on the brake pedal firmly, but not super hard, and keep the pressure on the pedal. If the pedal gradually goes all the way down to the floor, the master cylinder is bad.

说明慢慢在活塞 （Oring？）有漏。

所有跟帖： 

• 谢谢您！感恩节快乐 -wibblypig0- ♂ (0 bytes) () 11/23/2023 postreply 11:44:30

• 试过了，没有文中说的这个现象 -wibblypig0- ♂ (0 bytes) () 11/24/2023 postreply 05:53:31