Fig. 5.16. Location of cooling system elements (for clarity, the decorative engine cover has been removed): 1 - hose connecting the throttle assembly to the expansion tank; 2 - hoses connecting the cooling system to the heater radiator pipes; 3 - expansion tank hoses; 4 - expansion tank; 5 - Upper radiator hose; 6 - hose from the thermostat housing to the radiator
1. When inspecting the engine, pay attention to the presence of coolant in the expansion tank, the integrity of the rubber hoses and radiator (Fig. 5.16).
Helpful Hint: A burst hose can be temporarily repaired using duct tape.
Reinforced adhesive tape is especially well suited for this purpose (for example, silver color), which can be purchased at auto stores.
2. Inspect the connections to the radiator outlet...
3. ...and supply hoses.
4. Inspect the connections of the cooling system hoses to the heater radiator pipes...
5. ...and also the lead-in...
6. ...and the outlet hoses with the cylinder head.
Helpful Hint: If you detect a leak in any of the hoses where it connects to the pipe, drain the coolant. Squeeze the clamp with pliers and slide it along the axis of the hose.
Remove the hose from the branch pipe. As a rule, the cause of the leak is corrosion of the sealing surface of the branch pipes. Clean the damaged surface and install the hose on the sealant. After the sealant dries, fill in the coolant.
7. Check the hose connections to the expansion tank.
There are two valves installed in the expansion tank cap: inlet and outlet. The outlet valve plays a major role in ensuring the optimal temperature regime of the engine. It maintains excess pressure in the system of at least 0.14 MPa (1.4 kgf/cm²), ensuring an increase in the temperature at which the coolant begins to boil and preventing intensive vaporization. When the valve is jammed in the closed position, overheating causes a significant increase in excess pressure, which can lead to a rupture of the expansion tank or a tear in one of the hoses. In turn, jamming the valve in the open position leads to premature boiling of the coolant.
Therefore, once a year, wash the expansion tank plug with running water, and check the valve for sticking by pressing with a thin screwdriver. If in doubt, replace the plug.