Tools for testing the cooling system under pressure
4800-1 - Hand pump
4800-2 - Hose
4800-15 - Nozzle
Examination
Leaks in the cooling system and the operation of the safety valve in the cap can be checked with a commercially available tester. The following HAZET tools are suitable for this: hand pump 4800-1 with hose 4800-2 and nozzle 4800-15.
Attention! If the cylinder head gasket has been replaced, warm up the engine to operating temperature and allow it to cool before checking. This ensures the tightness of the cylinder head gasket.
When the engine is hot, cover the expansion tank with a thick cloth before opening it to prevent burns from hot coolant and steam. The cover should only be removed when the coolant temperature is below +90°C.
1. Turn the cap on the expansion tank ½ turn to the left and depressurize the cooling system. Then turn the cover further and remove it completely.
2. Set the heater switch in the passenger compartment to maximum power.
3. Check the coolant level, add coolant if necessary, refer to the appropriate section.
4. Install the tester on the fluid fill port. Using the pump of the device, create a pressure of approximately 1.4 atm. If the pressure drops, locate the leak and repair the leak.
Note. the illustration is informative and may not fully correspond to the model in question.
5. If the pressure drops and there is no fluid leakage, the cause may be internal leaks, for example, due to a damaged cylinder head gasket or due to a crack in the housing.
Checking the safety valve
The safety valve is located in the cap of the expansion tank. Its task is to open the cooling system and drain the liquid when a certain pressure is reached.
1. Screw on the cap (2) on the control device (1).
Note. the illustration is informative and may not fully correspond to the model in question.
2. Create the necessary pressure specified in the Specifications. The safety valve opens in two stages. The vacuum valve opens when a vacuum is created.
Note. The opening pressure of the valve is indicated on the cap in atm. x 100. If, for example, there is «140/200», we are talking about a two-stage cover and the valve opening pressure is 1.4 and 2.0 atm.