Warning: Start this procedure after the engine has cooled down. Do not allow antifreeze to come into contact with skin or painted body surfaces. If fluid does spill, wash it off immediately with plenty of water. Do not leave antifreeze in an open container near the workplace or on the garage floor. Children and pets may be attracted to the sweet smell of antifreeze, but be aware that ingesting it is deadly.
1. After the engine is completely cool, cover the expansion tank cap with a rag and slowly turn the cap counterclockwise to relieve pressure in the cooling system (a hissing sound is usually heard) (see fig. 31.1). Wait until the pressure in the system drops to normal atmospheric pressure and turn the cap so that it can be removed.
Pic. 31.1. Reducing the pressure in the cooling system by removing the cap of the expansion tank
2. Place a suitable container under the radiator, then install a piece of rubber hose into the drain nozzle (see fig. 31.2). Open the drain plug (below the nozzle), by turning it with a large screwdriver and allow the coolant to flow through the hose into a container.
Pic. 31.2. Radiator drain nozzle (shown by arrow)
3. Move the container so that it is located under the drain hole of the cylinder block, which is located on the right side of the cylinder block (see fig. 31.3). (Certain engines are equipped with drain holes with a combined nozzle to which a piece of rubber hose can be connected). Loosen the drain plug by turning it with an open end wrench and let the fluid drain into a container.
Pic. 31.3. Engine block drain nozzle (shown by arrow)
4. When the coolant is slig, remove the drain hoses and wrap the drain plugs of the cylinder block and radiator.
Flushing the cooling system
5. If the antifreeze has not been updated for a long time, or the cooling mixture is very diluted, then over time, the cooling system loses its effectiveness due to the fact that the inner walls of the radiator tubes corrode, become covered with scale and other deposits. The efficiency of the cooling system is restored by flushing it.
6. To avoid unwanted contamination, the radiator and engine are flushed separately.
Flushing the radiator
7. To flush the radiator, disconnect the top and bottom hoses and all other hoses from the radiator as described in Chapter 3.
8. Insert a garden hose into the top inlet. Run clean water through the radiator and continue flushing until clean water comes out of the bottom hole.
9. If no clear water flows out after a reasonable time, a flush with the addition of detergent additives will be required. It is important to strictly follow the manufacturer's instructions. If this does not lead to the desired result, it is necessary to insert the hose into the lower opening of the radiator and rinse it with a reverse flow of water.
Engine flush
10. To flush the engine, remove the thermostat as instructed in Chapter 3, then temporarily install the thermostat cover. Adjust the temperature control to the maximum value.
11. Disconnect the upper and lower hoses from the radiator. Insert a garden hose into the engine's top hose and run clean water through it. Continue flushing the engine until clean water flows from the bottom hole.
12. After flushing is complete, install the thermostat and connect the hoses as described in chapter 3.
Filling the cooling system
13. Before filling the cooling system, check that all hoses and clamps are in good condition and that the clamps are securely tightened. Recall that in order to prevent corrosion of engine parts, an antifreeze mixture should be used all year round (see next subsection).
14. Remove the expansion tank cap and prime the system by slowly pouring coolant into the expansion tank to prevent air pockets.
15. If the coolant is being replaced, first drink a couple of liters of water, then the required amount of antifreeze. After that, add water to the required level (see fig. 31.15, a, b).
Pic. 31.15, a. If the coolant is changing, start by adding a couple liters of water...
Pic. 31.15, b....then fill in the required amount of antifreeze and top up with water
16. As the fluid level in the expansion tank rises, compress the upper and lower radiator hoses to help expel trapped air in the system. When the air is expelled, add the liquid level to the mark "MAX". Close the expansion tank cap securely.
17. Where provided, remove the plug from the coolant sensor housing on top of the cylinder head. When the coolant begins to flow out, install the plug and tighten it. If fluid does not flow out of the hole, pour coolant into the open hole so that it starts to flow back. Install the plug and tighten it securely. This will remove air pockets from the cooling system that may interfere with the operation of the sensor (ov) cooling systems.
18. Start the engine and warm it up so that the thermostat opens - when this happens, the liquid from the radiator, flowing through the upper radiator pipe, will begin to heat it.
19. Check for leaks, especially around parts that have been removed. Check the coolant level in the expansion tank and top up if necessary. Recall that in order to accurately determine the level of coolant in the expansion tank, the system must be cold. If the expansion tank cap is removed while the engine is still warm, cover the cap with a thick cloth and slowly unscrew the cap to relieve the pressure in the system (a hissing sound is usually heard). Wait until the pressure in the system drops to normal atmospheric pressure and turn the cap so that it can be removed.
Antifreeze mixture
20. Antifreeze must be changed on time. This is necessary not only to preserve its properties, but also to prevent corrosion of the metal, which can occur over time when the effectiveness of the anti-corrosion inhibitors is lost.
21. Always use ethylene glycol based antifreeze, which is recommended for use in multi-metal cooling systems. The amount of antifreeze and freezing point are indicated in the section "specifications".
22. Before filling with antifreeze, the cooling system must be completely drained, preferably flushed. Check the condition of all hoses.
23. Once the system has been filled, affix a label to the expansion tank stating the type, concentration of antifreeze, and fill date. All subsequent top-ups must be done with the same type and concentration of antifreeze.
24. Do not use antifreeze in windshield/tailgate washers as this will damage the vehicle's paintwork. Special windshield washer additives should be added in the quantities indicated on the bottle labels.