2. Carefully unscrew the radiator cap and wipe thoroughly with a rag from the inside. Wipe the radiator neck, the presence of corrosion or oil on the neck indicates the need to change the coolant (the presence of oil indicates a violation of the tightness of the cylinder head gasket). The fluid inside the expansion tank and radiator should be relatively clean and clear. If the fluid is rusty or has an oily film, then drain the fluid, flush the system and fill in fresh coolant in the correct proportion.
3. Carefully check the radiator and heater hoses along their entire length. If blisters, cracks or mechanical damage are found, replace the hoses (see photo). Cracks in the hose are best seen when it is bent. Pay special attention to the clamps that secure the hoses to the parts of the cooling system.
![](https://www.chevyman.ru/img/tahoe/0225.jpg)
4. Check for signs of leakage on all parts of the cooling system (including hoses, connectors, etc.). Traces of a fluid leak usually appear as a white coating or rust. If such traces are found on the parts of the system, replace the part or gasket. Replace all pins (wire) clamps on clamps with screw tightening.
5. Clean the front of the radiator from insects, leaves, etc. that have invaded the grille. Be careful not to damage the radiator tubes.