我厂有一台ＺＬ４０装载机，在作业时发现其动臂提升缓慢，液压系统噪声异常。开始我们认为是液压系统内泄或是液压油箱泊位太低等原因，可进行常规检查时却一切正常，只是听到液压系统中工作泵发出的异常噪声，于是我们检查工作泵，结果发现在发动机高速运转时工作泵的进油管 Our factory has a ZL40 loader, found in the operation of its boom to slow, hydraulic system noise anomalies. Initially we think that the hydraulic system or the hydraulic system is too low due to berths and other reasons, can be routine inspection but everything is normal, but to hear the abnormal noise pump hydraulic system, so we check the working pump and found that the engine High-speed operation of the pump into the pipe