1台宣化T140型推土机在施工作业过程中,出现左、右转向失灵现象。将发动机熄火停机1h,待传动系统温度降低后,再启动发动机方能使该机继续工作。但该机工作30min后又不能转向。分析认为,该推土机转向失灵原因可能有以下几点:一是转向齿轮泵输出的油液达不到额定压力,不能将离合器分离;二是转向油液质量不合格,油液 1 Xuanhua T140 bulldozer in the course of construction operations, turn left and right turn failure phenomenon. Turn off the engine 1h, until the temperature of the transmission system is reduced, and then start the engine to make the machine continue to work. But the machine can not turn 30min after work. Analysis, the bulldozers turn failure may have the following reasons: First, turn the gear pump output of oil less than the rated pressure, can not be separated from the clutch; Second, the quality of the steering fluid failed, the fluid