一辆93款三菱帕杰罗越野乘用车(未采用ABS系统),其前轮制动器为盘式,后轮制动器为鼓式。在刚行驶时两前轮制动状况良好,当行驶了一段路程后两前轮无制动,而两后轮制动正常。一般情况下,盘式制动器的制动效能要优于鼓式制动器,而该车却恰恰相反。经分析认为造成该故障的原因有以下三个方面:一是前轮制动器本身有故障;二是制动主缸有故障;三是制动感载阀有故障。检查前轮制动器。检查前制动管路,发现管路中并无空气,也无 A 93 Mitsubishi Pajero off-road passenger car (ABS system is not used), the front wheel brakes for the disc, the rear brakes for the drum. The two front brakes were in good braking condition just as they were driving. After traveling for some distance, the two front wheels did not brake and the two rear wheels were in normal braking. Under normal circumstances, the disc brake braking performance is better than the drum brake, but the car is just the opposite. The analysis shows that the cause of the failure has the following three aspects: First, the front wheel brake has its own fault; second, there is a brake master cylinder fault; third brake sense valve is faulty. Check the front wheel brakes. Check the brake line before and find no air in the line and nothing