To do this, install the thermostat on the stand BS-106-000, lowering it into a tank with water or coolant. From the bottom to the main valve 9 (pic. 2-66) support the indicator leg bracket.
Pic. 2-66. Thermostat: 1 - inlet pipe (from the engine!; 2 - bypass valve; 3 - bypass valve spring; 4 - glass; 5 - rubber insert; 6 - outlet pipe; 7 - main valve spring; 8 - main valve seat; 9- main valve; 10 - holder; 11-adjusting nut; 12 - piston; 13 - inlet pipe from the radiator; 14 - filler; 15 - clip; D - fluid inlet from the engine; P - fluid inlet from the radiator: H - fluid outlet to the pump
The initial temperature of the liquid in the tank should be 73-75°C. Increase the temperature of the liquid gradually by about 1°C per minute with constant stirring, so that it is the same throughout the volume of the liquid.
The valve opening temperature is taken to be the one at which the main valve stroke is 0.1 mm The thermostat must be replaced if the main valve opening temperature is not within (80±2) °C or main valve stroke less than 6.0 mm. The simplest thermostat test can be carried out by touch directly on the car. After starting a cold engine with a working thermostat, the lower radiator tank should heat up when the needle of the liquid temperature gauge is approximately 3-4 mm from the red zone of the scale, which corresponds to 80-85°C.