The thermostat of the engine cooling system is removed for inspection or replacement
The main symptoms of engine cooling system thermostat failure: - engine overheating or insufficient engine warming up
For ZMZ-406 engine
Drain the liquid from the cooling system, article - "Replacing the engine coolant"
Disconnect the two hoses from the pipes of cover 1 of the thermostat housing.
Unscrew two bolts 2 and remove cover 1.
If you need to remove the thermostat housing, you need to disconnect the wires from the sensors 5, loosen the tightening of the clamps 4 and, after unscrewing the two bolts 3, remove the thermostat housing.
Remove thermostat 1 from housing 2.
Install the new thermostat in reverse order.
With ZMZ-402 engine
Drain the cooling system.
Disconnect hoses 1 and 2 from cover 6 of the thermostat housing, having first loosened the clamps.
If you need to remove the thermostat housing, you need to disconnect hose 3 from it and wire 4 from the coolant temperature sensor.
Unscrew two bolts 5 (the second bolt from the bottom of the housing) and remove the thermostat housing.
Unscrew the two bolts 1 and remove the cover 2. Remove the thermostat 3 from the housing.
Install the new thermostat in reverse order.