During the maintenance process in winter, there always comes out with the problems such as antifreeze entering into the lubricating oil, water leakage of radiator, etc. In addition, changing the diesel oil and lubricating oil is the indispensable link before the severe winter comes. So, it is necessary to make fully preparation for the winter maintenance.

1. Selection of High-quality Antifreeze
There are two main indexes measuring the quality of the antifreeze. One is the freezing point. The ordinary antifreeze can make it get to -40℃. While, the freezing point of the high-quality antifreeze can be as low as -60℃. The other index is boiling point. For the antifreeze, the boiling point should be at least 108℃.

The anticorrosion performance of the antifreeze also plays an important role. It directly relates to the working life of the cooling system of the equipment. Moreover, the anti-scale property also should be taken into account. More than 65% of cooling systems of equipment have water scale and rust which affect the cooling function of the cooling system significantly. So, before changing the antifreeze, it is better to clean up the water scale and rust in the radiator first.

Under normal circumstances, the antifreeze should be changed every year. After the service for one year, each index of the antifreeze decreases and cannot reach the original protective requirements. Additionally, you should know that different types of antifreeze cannot be mixed to avoid chemical reaction, deposition or bubbles.

2. Water Pump Inspection
After changing the antifreeze, some equipment is found to have the phenomenon of lubricating oil containing antifreeze. This is because the water seal of the water pump comes out with aging failure causing that the antifreeze enters into the lubrication chamber through the water seal and finally arrives at the oil pan. So, you should observe the lubricating oil level carefully after changing the antifreeze. If the lubricating oil level rises, you should stop the equipment and check it immediately. Commonly, changing the water seal or assembly of the water pump is taken for use.

After the repair work, you need to make the machine stay in the no-load idling state to use the new lubricating oil taking away the antifreeze residue in the engine's lubricating system. Please note that you should shorten the interval for the following lubricating oil changing to ensure that the lubricating system of the diesel engine functions normally.

3. Anticorrosion Filter Element of Cooling System
The anticorrosion filter element of the cooling system contains the additives such as ion exchange resin, anticorrosive agent, magnesium board, etc. It can effectively protect the parts. The ion exchange resin can prevent the formation of the water scale. The anticorrosive agent can form the corrosion protective film in the coolant jacket to avoid the oxidation. For the magnesium has stronger metal activity than the ferrum, the corrosive ions in the coolant react with the magnesium board first, which can effectively prevent the iron from corrosion. Additionally, the anticorrosion filter element can also filter rust, water scale and sediment.

The anticorrosion filter element should be replaced over the same period of antifreeze. Meanwhile, it should be replaced after the engine working for 1000 hours to keep the effective protective function.

4. Fuel Oil System Maintenance
A. Normal Use of Fuel
The user should choose the diesel oil in line with the local temperature as well as the cold filter plugging point and freezing point of diesel oil.
B. Maintaining the Fuel Oil System
The user should clean the oil mist separator thoroughly by keeping clean surface, checking the discharging mark and timely discharging impurities. The oil mist separator should be replaced if it cannot be cleaned up. Then, clean the diesel oil tank by removing the sediment at the bottom.
C. Replacement of Oil Atomizer with Bad Atomization
Check the fuel injection pump to avoid bad working condition for keeping the normal working of the diesel engine.

5. Selection of Lubricating Oil
The user should select the lubricating oil by considering the local temperature with the solidifying point, pour point and viscosity of lubricating oil. The lubricating oil with high solidifying point cannot be used at low temperature. Contrarily, in the high temperature region, there is no necessary to use the lubricating oil with low solidifying point. The solidifying point and pour point are both the indexes for measuring the low temperature fluidity of lubricating oil. They have no principled distinction. The difference is just the slightly different testing methods. The same lubricating oil has not exactly the same solidifying point and pour point. Generally, the pour point is higher than the solidifying point by 2 to 3℃.

6. Inspection for Water, Oil and Gas Leakage
The seal component of hydraulic system, gas circuit and water piping, especially the seal components such as rubber O ring and rectangular sealing ring, is prone to have the phenomenon of expanding with heat and contracting with cold. When the temperature is below 0℃ continuously, the equipment would turn to have the water leakage, oil leakage and gas leakage, especially when the temperature is close to -10℃ continuously. Before the winter comes, the user should check the equipment about the leakage phenomenon thoroughly to eliminate the leakage and hidden fault.

7. Maintenance for Electrical Equipment
In winter, the aging equipment is difficult to be started. Therefore, checking and changing the aging electrical circuit and parts is the essential measure in winter maintenance for mitigating the starting difficulty. Moreover, the accumulator should also be taken into the maintenance range.

The heating equipment is the indispensable device in outdoor operation in winter. So, it should be checked and repaired to guarantee normal work in winter.