So how do we get rid of the air in the cooling system after replacing the antifreeze? Let's talk about the simplest exhaust method of engine cooling system, which is suitable for many models.
This method is that we remove the small water pipe at the top of the engine, just like the picture above, and remove the return pipe at the top of the water tank to expose it. At this time, we add new antifreeze to our cooling system, slowly add it, and then add the coolant to the removed water pipe.
But remember how much antifreeze we added. If the antifreeze in the cooling system is completely replaced in a normal engine, we need to add about 4 liters of antifreeze. If we use this exhaust method, we have added 4 liters of antifreeze, and there is new antifreeze in the removed water pipe. Do you know how to change antifreeze correctly and how to vent? What do you usually do?
Then we have successfully exhausted the air in this way. Finally, put the water pipe back, then start our engine to turn the warm air to the maximum, and then keep the engine speed at about 3000 rpm until our warm air system blows out hot air.
Finally, check whether the fan on the water tank of our engine compartment is working and hot air is blown out, which means that our entire exhaust and the replacement of our cooling system are completed. Another way is that many of our cars have added a small screw to vent the air in the cooling system. This screw is usually located on the water pipe of our water tank cooling system. It's easy to vent with this screw.
We only need to unscrew this screw when adding new antifreeze, and then add new antifreeze until the new antifreeze flows out of this screw. After replacing the antifreeze, start the vehicle and wait for the cooling fan to run at idle speed. Because the thermostat in the cooling system is completely open at this time, it is necessary to slowly open the water tank cover because there will be pressure. Check the scale of antifreeze after opening, and add it to the standard scale if it is missing. After repeating it twice, the air in the cooling system will be exhausted. At the same time, antifreeze should be added to the standard scale.
The full name of antifreeze is antifreeze coolant. It has two functions: to prevent the vehicle from freezing when it is not started, because the antifreeze is in the cylinder, and the volume will expand when the liquid becomes solid, so it will freeze and crack the cylinder. Another function is to cool the engine after the vehicle is started. Prevent the engine from being damaged due to excessive temperature. Antifreeze also plays a role in managing rust prevention and preventing pipeline blockage caused by excessive scale.
After the vehicle is replaced with antifreeze, the first thing to do is the intake and exhaust of the coolant circulation system. Do you know how to change antifreeze correctly and how to vent? What do you usually do?
If the coolant filler is above the water tank, we can add antifreeze to it when adding antifreeze. From the filler, we can see that we can temporarily stop filling antifreeze without adding too much, and then start the engine and let it warm up slowly. At this time, the thermostat of the engine is closed. There will be some air in the water channel in the engine, which will hinder the normal circulation of coolant. This phenomenon is also called air resistance. As the water temperature rises, the thermostat valve will keep opening. At this time, we will see that the water level in the water tank will drop, and we can slowly pour some antifreeze into the water tank according to the situation. Do you know how to change antifreeze correctly and how to vent? What do you usually do?
At the same time, antifreeze will flow out from the water inlet pipe of the water tank, which is the return pipe of the engine. In general, the water inlet pipe of the water tank is very close to the filling port of the water tank, and we can see that antifreeze is flowing out of return pipe. Pay attention to safety when observing antifreeze to avoid being scalded by antifreeze gas. When you see that there is no gas disk in fertilizer and water management, only liquid flows, basically the gas in the circulation system is almost exhausted. At this time, the cooling fan of the water tank should also be turned on. We are slowly pouring antifreeze into the water tank from the filler. Generally, it is enough to pour antifreeze at the lower position of the water tank mouth. After the cooling fan stops running, cover the water tank, then open the cover of the make-up water tank, and add antifreeze to the make-up water tank to the middle position between the upper line and the lower line.
When some models are filled with antifreeze, the engine thermostat will have an exhaust valve. This valve body has some plastic exhaust valves and some bolt exhaust valves. You can open the exhaust valve next to the thermostat before adding antifreeze, and then close the valve after the antifreeze flows out. This exhaust mode is faster than the previous one, but it is only applicable to some models.
Some models will install an exhaust hose next to the water-saving valve at the inlet pipe of the small water tank of the heater. We only need to open this hose when the engine is running, so that the coolant can run normally in the system, and the gas in the system will be discharged from this pipeline, and the way to confirm the removal is that the antifreeze will continue to flow out from this hose. Then close the hose again, and exhaust can be completed. Do you know how to change antifreeze correctly and how to vent? What do you usually do?
Some models have no opening for adding antifreeze on the water tank, and only add antifreeze from the opening of the water replenishment tank. Such a cooling system only needs to open the water supply tank cover, so that the cooling liquid can circulate normally in the system. Don't add too much antifreeze when filling, as long as the antifreeze is close to the bottom dead center of the water replenishment tank. Then when the liquid level of antifreeze drops, continue to slowly add antifreeze to the make-up water tank. You can be sure that the air in the coolant system has been exhausted, until you see the antifreeze continuously flowing out of the return pipe.
Then add antifreeze between the top dead center and the bottom dead center, and cover the water supply box cover, and the whole work of replacing antifreeze is completed. Attention. After replacing the antifreeze, we need to wash the antifreeze spilled on the engine, water tank and car body with hot water. Avoid the corrosion of antifreeze to car paint and vehicle parts. Do you know how to change antifreeze correctly and how to vent? What do you usually do?
Antifreeze, as the name implies, has the most obvious function, and also has the characteristics of waterproof scale. It is not easy to freeze at low temperature and boil at high temperature. Try to choose big brand antifreeze as the main carrier of engine heat dissipation, or it is better to change it. Moreover, the quality of antifreeze on the market is uneven, divided into red and green. Good antifreeze generally does not stain your hands. The color of antifreeze is only to prevent the cooling system from leaking, so we can easily find the leaking point. The engine cooling system is mainly composed of water pump, water pipe, water tank, cooling fan and thermostat.
Then why exhaust? Because the cooling system can't have air, if there is air, the water pump won't pump water and the water can't circulate. The exhaust of every car is basically the same, but some cars don't need it. Generally, the exhaust screw is on the sewer pipe (that is, the water inlet pipe) or the water inlet pipe (the water outlet pipe), and some car owners don't have to beat the air. If it has been a car with water before, it is recommended to clean it with water tank cleaner before replacing antifreeze. Moreover, antifreeze also has a service life. It is recommended to replace it every two years. After the replacement, you should start to observe the water temperature of the engine. After the cooling fan rotates, it depends on whether it is hot air or cold air, whether the fan will stop and whether the water pipe leaks. It is recommended to replace it in the repair shop. Do you know how to change antifreeze correctly and how to vent? What do you usually do?