There are two types of malfunctions when a bulldozer cannot move: when the engine starts and runs at a medium speed, and then shifts gears, the bulldozer cannot start immediately; The heat engine cannot start immediately; The thermal engine cannot move, which means that the bulldozer cannot start immediately within the normal oil temperature range of the tanker; The thermal engine is unable to move due to malfunction.
When the bulldozer is unable to move due to a malfunction, regardless of whether the engine is still in a hot state, the engine should first control the throttle to run at medium high speed, and then remove the left foot pedal of the cab to observe whether the output shaft of the cab is rolling. If there is rolling, check if the output shaft still rolls after shifting, and also pay attention to whether the engine, torque converter, and transmission sounds change before and after shifting. If the output shaft does not roll after hanging, it indicates that the fault is caused by the torque converter, such as a lack of oil in the torque converter; If the output shaft can roll both before and after shifting, it is confirmed that there is no fault in the torque converter, and the fault may be in the transmission, steering clutch, brake, etc.
To distinguish whether it is a fault in the oil system or the mechanical department, you can loosen the exhaust screw on the variable speed fine filter and check for air. If there is air but it has not been completely discharged, confirm that there is an air intake between the low-pressure oil circuit, i.e. the oil suction port, and the variable speed pump. To further determine whether there is air intake, it is necessary to confirm that there is air intake between the low-pressure oil circuit, i.e. the oil suction port, and the variable speed pump. To further determine whether the air intake is between the coarse filter and the variable speed pump. If there is no air in the exhaust screws of the variable speed fine filter and the steering fine filter, it is confirmed that the fault is not in the steering oil system, but in the transmission, steering clutch or brake positions.
