DJK

刹车踩下去，就象刹了气的皮球一样，保持不住压力。高手指点江山，咋办？

DonCherry

You are right, there might be AIR in the break
system. Do a research about how bleeding the
break system. Anyway, you need a partner to help
you.

Don

sleeper

你需要将车轮卸下，将刹车油缸放气孔打开一点，配合刹车将气放掉。