单项选择题
A.permanent loss of pump suction
B.worn shaft seals
C.high level in the oil sump
D.low motor RPM
单项选择题 Air trapped in the hydraulic fluid of a steering system would be indicated by（）
单项选择题 How can the chance of contaminating hydraulic fluid be decreased when working on hydraulic system?（）
单项选择题 In the design of hydraulic piping and equipment consideration is given to minimize turbulence in the hydraulic fluid, as this will cause（）