Removal
1. Drain the coolant.
2. Remove the service cover.
3. Remove the thermostat cover 4 (figure 3.29a).
4. Remove thermostat 2.
Figure 3.29a, Removing and installing the thermostat: 1 - Cooling system pump; 2 - Thermostat; 3 - Sealing ring; 4 - Thermostat cover; 5 - Bolt; 6 - Cooling system pipe.
Examination
5. Place thermostat 1 on the wire in a vessel with water (figure 3.296).
6. Measure the water temperature.
7. Heat the water to the temperature of full opening of the bypass valve 1/2 of the thermostat. Thermostat opening temperature: 83°C. Main valve opening temperature: 95°C. Main valve travel: 8 mm. Bypass valve closing: 92°C.
8. Heat the water until the main valve 1/1 of the thermostat is fully opened and measure its movement. The main valve should be fully open for 6 to 8 minutes. Otherwise, the thermostat must be replaced.
Installation
9. Installation is carried out in the reverse order of removal.
Figure 3.29b. Checking the thermostat: 1 - Thermostat; 1/1 - Main valve; 1/2 - Bypass valve