(一) 一台小四轮拖拉机,工作中机油压力不稳,机手判断为机油泵工怍不正常。在拆卸修理机油泵时不慎撕坏垫片,机手就用白纸壳自制两个纸垫代替。安装后机油压力仍不稳,不一会,发动机冒黑烟且很快熄火。经检查发现因机油泵密封不好,机油压力不足造成烧瓦。同时还发现原故障 (A) A small four-wheel tractor working in the oil pressure instability, the engine operator to determine the engine oil pump is not normal. In the demolition repair pump accidentally damaged when the gasket, the machine handmade white paper shell made of two paper pad instead. Oil pressure is still unstable after installation, a short while, the engine black smoke and quickly turn off. After inspection found that the oil pump seal is not good, oil pressure caused by burning tiles. Also found that the original fault