保护系统油路
protective system oil line
闭合油路回油道
loop circuit return passage
差动转向润滑油路
differential steer lubrication circuit
铲刀升降液压油路
blade lift hydraulic circuit
超龄油路
overage bitumen pavement
overage bitumen road
overaged bitumen pavement
超龄油路养护
overage bitumen pavement maintenance