1、摩擦片磨损严重，间隙过大，离合器自动倒空阀密封不严，使压力下降；
Friction plate wear serious, the gap is too large, the clutch automatic emptying valve Mifengbuyan, the pressure drop;

2、换挡操纵阀管路堵塞，切断阀不能回位；
Shift control valve pipe plug, shut-off valve can not return;

3、变速阀定位弹簧疲劳或折断，钢球跳动，离合器活塞环，密封圈磨损严重，使泄露严重。
Fatigue or shift valve positioning spring break, beating balls, clutch piston rings, seals badly worn, so serious leak.