Cooling System

Coolant Hose Connection Diagram

• Blue = large coolant circuit.

• Brown = heating circuit.

• Green = fuel system coolant circuit.

• Orange = Exhaust Gas Recirculation (EGR) coolant circuit.

• Red = small coolant circuit.





1 Fuel System Cooler

• Change coolant after replacing.

2 Fuel Cooler Pump (V166)

3 Non Return Valve

• Arrow points in direction of flow.

4 Radiator

• Change coolant after replacing.

5 Engine Coolant Temperature (ECT) Sensor (on Radiator) (G83)

6 Bleeder Screw

7 Coolant Thermostat

• For the EGR coolant circuit.

8 Coolant Thermostat

9 EGR Cooler Pump (V400)

• In the EGR coolant circuit.

10 Generator

11 Engine Oil Cooler

12 Cylinder Head Bank 1 (Right)

• Change coolant after replacing.

13 Coolant Expansion Tank

• Replace the seal if damaged.

• Perform a cooling system leak test using cooling system tester (V.A.G 1274) and adapter (V.A.G 1274/8).

• Check the cap using cooling system tester (V.A.G 1274) and adapter (V.A.G 1274/9).

• Test pressure 1.4 to 1.6 bar

14 Coolant Expansion Tank Cap

15 ECT Sensor (G62)

16 Bleeder Screw

17 EGR Auxiliary Cooler

18 EGR Cooler

19 EGR Cooler Bypass Valve

20 from Heater Core

21 to Heater Core

22 Cylinder Head Bank 2 (Left)

• Change coolant after replacing.

23 Cooling Element

• On the fuel filter.

24 Bleeder Screw

25 Coolant Thermostat

• For the EGR coolant circuit.

• With the EGR motor (V338)

26 Coolant Pump

27 Bleeder Screw