1、摩擦片磨損嚴重，間隙過大，離合器自動倒空閥密封不嚴，使壓力下降；
Friction plate wear serious, the gap is too large, the clutch automatic emptying valve Mifengbuyan, the pressure drop;

2、換擋操縱閥管路堵塞，切斷閥不能回位；
Shift control valve pipe plug, shut-off valve can not return;

3、變速閥定位彈簧疲勞或折斷，鋼球跳動，離合器活塞環，密封圈磨損嚴重，使泄露嚴重。
Fatigue or shift valve positioning spring break, beating balls, clutch piston rings, seals badly worn, so serious leak.