When starting a diesel engine in cold season, sometimes the pump shaft will be broken. The first reason is the quality problem of the pump shaft itself, and the second is caused by human factors.
The quality of the water pump shaft itself is not good, just replace it. Human factors often occur in autumn and winter. If the cooling water in the diesel engine is not discharged in time after the construction machinery operation, a small amount of cooling water will remain in the gap between the pump impeller and the sealing ring. When the temperature is too low, the pump impeller will freeze to death. If the diesel engine is started at this time, the water pump shaft is easy to be twisted. To prevent this kind of failure, the water in the gap of impeller chamber must be completely removed. There are four methods
1. The starter drives the crankshaft to run idly to drain water. Park the construction machinery on a flat area, open the diesel engine water radiator cap and all drain switches, drain the water inside the cooling system, and then use the starter to drive the crankshaft to rotate for 5 ~ 10s. Make sure that the diesel engine throttle is in the position of no oil supply.
2. Adopt compressed air drainage method. After the diesel engine is drained in a flat area, a self-made joint, which is similar to the water filling cap, is screwed on the water filling port of the water radiator to continuously supply air to drain the water in the cooling water pump for several times.
3. Add a little antifreeze for drainage. After the construction machinery is parked on a flat area and the cooling water is drained, 3 ~ 5L antifreeze is added to the water supply radiator, and the crankshaft is driven to rotate by the starter without oil supply to drain the residual water in the water pump. If the starter cannot be used, the fan can be pulled by hand or pedaled to drive the crankshaft to rotate several times.
4. The method of drainage by stages is adopted. When the temperature is above 0 ℃, after the first drainage on the flat section, wait for 10 ~ 15min, turn on the drain switch, and then use the compressed air drainage method to drain all the water in the pump. You can also blow air from the water inlet to the water radiator at intervals. If you can't see water dripping from the water outlet, it means that the water in the water pump has been drained.
