111 Series Engine Thermostat Working Element Installation Details
1. The installation details of the working element of the thermostat of the 111 series engine are shown in the illustration, to which all references in the text refer.
2. Drain the cooling system (see Chapter Checking the cooling system and frost resistance of the coolant, replacing the liquid).
3. Remove the top front cover.
4. Disconnect the cooling system hoses (2 and 4).
5. Unscrew the fastening bolts (1) and remove the thermostat cover (27) with the working element (27a) built into it from the thermostat casing (30).
Attention! To avoid irreversible damage, the working element should not be removed from the cover! If necessary, the element is replaced together with the cover.
6. Installation is carried out in reverse order.
7. Finally, check the cooling system for signs of developing leaks.
Thermostat assembly with casing
111 Series Engine Thermostat Assembly Installation Details
1. The installation details of the 111 Series Engine Thermostat Assembly are shown in the illustration to which all references in the text refer.
2. Remove the cooling fan assembly with viscous coupling (1).
3. Drain the cooling system (see Chapter Checking the cooling system and frost resistance of the coolant, replacing the liquid).
4. Remove the power unit cover (16).
5. Disconnect the cooling system hoses (2, 3 and 4).
6. Disconnect the electrical wiring and vacuum lines from the thermostat housing mounted temperature sensor (30).
7. Remove the eye (6).
8. Unscrew the mounting bolts (7, 8 and 9) and remove the thermostat housing (30) together with the cover (27).
9. Carefully clean the sealing surface, prepare a replacement sealing ring (31).
10. If the thermostat housing needs to be replaced, remove the temperature sensor from it.
11. Installation is carried out in reverse order.
12. Finally, check the cooling system for signs of developing leaks.
M112/113
Thermostat Assembly Installation Details for Series 112 and 113 Engines
1 - Thermostat housing; 2 - Sealing ring; 3 - Mounting bolts; 4 - Clamp; 5 - Cooling tract hose; 6 - Radiator
1. The thermostat installation details for series 112 and 113 engines are shown in the illustration to which all references in the text refer.
2. Drain the cooling system (see Chapter Checking the cooling system and frost resistance of the coolant, replacing the liquid).
3. Remove the powertrain trim panel/air cleaner assembly.
4. Disconnect the cooling system hose (5).
5. Unscrew the mounting bolts (3) and remove the thermostat housing (1) together with the working element.
Attention! To avoid irreversible damage, the working element should not be removed from the cover! If necessary, the element is replaced together with the cover.
6. Installation is carried out in reverse order.
7. Finally, check the cooling system for signs of developing leaks.
Diesel models
M612
612 Series Engine Thermostat Installation Details
9 - Thermostat housing; 14 - Fitting; 16 - Bolt; 17 - Cooling tract hose; 18 - Ventilation hose; 20 - Fuel line support bracket; B11/4 - Coolant temperature sensor
Coolant Temperature Sensor Installation Details for 612 Series Engine
1 - Coolant temperature sensor; 2 - Electrical wiring connector; 3 - Retainer; 4 - Sealing ring
1. The installation details of the thermostat and coolant temperature sensor for the 612 series engine are shown in the illustrations to which all references in the text refer.
2. Drain the cooling system (see Chapter Checking the cooling system and frost resistance of the coolant, replacing the liquid).
3. Remove the cylinder head cover trim panels.
4. Disconnect the electrical wiring from the coolant temperature sensor (B11/4).
5. If necessary, remove the retainer (3) and take out the sensor (1), - prepare a new sealing ring (4).
6. Remove the fuel line support bracket (20). Disconnect the cooling (17) and ventilation (18) lines from the thermostat housing (9).
7. Remove the thermostat housing (9), pay attention to the installation position of the connecting nipple (14), prepare a new sealing gasket.
8. Installation is carried out in reverse order.
9. Finally, check the cooling system for signs of developing leaks.
M628
628 Series Engine Thermostat Installation Details
1 - Upper air duct; 2 - Cooling tract hose; 3 - Thermostat housing; 3a - Sealing ring; 4 - Air duct mounting support bracket (does not apply); 4a - Screws; 5 - Cooling tract hose
1. The thermostat installation details for the 628 series engine are shown in the illustration to which all references in the text refer.
2. Remove the bypass hose of the air boost tract.
3. Disconnect the cooling system hose (2) from the thermostat housing (3).
4. Remove the thermostat housing (3) together with the working element, - prepare a replacement sealing ring (3a).
5. Installation is carried out in reverse order.
6. Finally, check the cooling system for signs of developing leaks.
[Article was borrowed from the website mercedesman.ru]