Cooling System Cleaned
WM 190129 Cooling system cleaned (oil/coolant mixture)
Special tools
Cleaning the cooling system
Caution
Danger of scalding! Coolant can be very hot. Wear suitable protective equipment.
1. Repair the damaged component. Repair or replace the component which is causing the oil/coolant mixture.
2. Open hood.
3. Open tank cap on the expansion tank and remove.
4. Remove the entire underbody cover.
5. Drain cooling system. Remove the drain plug from the engine, drain the coolant into a container and dispose of coolant according to the country-specific legal requirements.
6. Pull the radiator supply and return lines off the engine. To do so, undo the hose clamps, carefully pull off the hoses and allow the remaining coolant to run out. Then connect the hoses again and tighten the hose clamps.
7. Tighten the drain plug on the engine. Tightening torque: 10 to 15 Nm (7.5 to 11 ftlb.).
Filling, bleeding and cleaning coolant circuit
Filling coolant circuit with cleaning fluid and bleeding
1. Screw lid adapter for coolant expansion tank (K 22) onto the expansion tank.
2. Connect the flexible extension (Fz 100 K) to the lid.
3. Connect the vacuum pressure gauge of the bleeder tool to the flexible extension. When doing so, ensure that both shutoff valves are closed (positioned 90° to flow direction)
4. Connect the Venturi nozzle onto the vacuum pressure gauge.
Information
^ The radiator cleaning agent which is prepared must be approx. 2 liters more than the amount which has to be filled.
^ The cleaning agent is mixed in a ratio of 50:50.
5. Place a canister with approx. 23 l coolant cleaning agent (mixed with 50% water) near to the coolant expansion tank.
6. Connect the filler hose -(5)- of the vacuum pressure gauge at the canister connection; put the return line -(6)- of the Venturi nozzle into a collecting container.
Information
^ A hissing sound after connecting the compressed air supply is usual.
^ An air pass in the return line -(6)- should not be obstructed.
7. Connect compressed air supply.
8. Open both shutoff valves on the vacuum pressure gauge until the transparent filler hose has completely filled with coolant.
9. Close the left shutoff valve (V1) on the vacuum pressure gauge and build up vacuum in the coolant circuit.
Information
^ If a vacuum does not build up, there is a leaking valve in the coolant circuit.
^ Deformation of the rubber hose of the cooling system is normal.
^ If the indicator of the pressure gauge is in the green area of the display scale, enough vacuum has been built UP
^ After both shutoff valves on the vacuum pressure gauge have been closed and the compressed air supply has been unplugged, the vacuum must not drop. If the vacuum drops within approx. 30 seconds, there is a leaking point in the coolant circuit.
10. When there is enough vacuum in the cooling system (indicator is in the green area), close the right shutoff valve (V2) and subsequently unplug the compressed air supply.
11. Reopen the left shutoff valve (V1) on the compressed air pressure gauge. The cooling system will now be filled. This procedure will take approx. 5 minutes.
12. When there is no trace of vacuum present or the coolant is no longer suctioned from the canister, open the right shutoff valve (V2).
13. Subsequently remove the complete filling tool (including the lid K 22).
14. Screw on the cap of the expansion tank.
Cleaning the cooling system
1. Start vehicle.
2. After the vehicle has been bled and the coolant temperature is 80 degrees C, let the stationary vehicle run at medium speed for at least 15 minutes.
3. Switch off engine.
Caution
Danger of scalding
^ Allow the coolant to cool down before opening the coolant circuit.
-> Coolant can be very hot.
-> Wear suitable protective equipment.
4. Slowly and carefully open the coolant expansion tank.
5. Unscrew the coolant drain plug on the engine and drain and collect the radiator cleaning agent. Disposal should be carried out according to the country-specific legal requirements.
6. Pull the radiator supply and return lines off the engine. To do so, undo the hose clamps, carefully pull off the hoses and allow the remaining liquid to run out.
7. Rinse away any adhering oil in the coolant expansion tank with hot water.
8. Connect the hoses again and tighten the hose clamps.
9. Tighten drain plug on the engine with a tightening torque of 10 Nm (7.5 ftlb.) to 15 Nm (11.0 ftlb.).
Information
^ Points 1 to 9 must be repeated until no more oil rises to the surface in the coolant expansion tank.
10. Fill the coolant circuit with water only and then bleed the cooling system according to the regulations.
11. Start engine.
12. After the vehicle has been bled and the coolant temperature is 80 degrees C, let the stationary vehicle run at medium speed for at least 15 minutes.
13. Switch off engine.
Caution
Danger of scalding
^ Allow the coolant to cool down before opening the coolant circuit.
-> Coolant can be very hot.
-> Wear suitable protective equipment.
14. Carefully open the coolant expansion tank and reduce the existing residual pressure.
15. Unscrew the coolant drain plug on the engine and drain the radiator cleaning agent.
16. Pull the radiator supply and return lines off the engine. To do so, undo the screw-type hose clamps, carefully pull off the hoses and allow the remaining water to run out.
Information
^ All hoses which have been removed during work on the cooling system must be replaced.
^ The Y-piece in the cooling system must be replaced.
17. Remove and replace hoses which have been pulled off fittings.
18. Replace the Y-piece on the vehicle underbody.
19. To do so, open the three fastening clamps with commercially available spring-band clamp pliers and pull off the Y-piece. Clean the flange with a cloth soaked in solvent naphtha and fit the new Y-piece.
20. Clean the flanges of the coolant circuit. Use a cloth soaked in solvent naphtha and clean the flanges from which the coolant hoses have been disconnected.
Information
^ The coolant hoses may only be coated with water as a lubricant to make the fitting of the hoses easier.
^ Never treat coolant hoses with spray oil.
21. Connect the new coolant hoses again and tighten the screw-type hose clamps or the spring-band clamps.
22. Fit coolant drain plug with new sealing ring. Tightening torque 10 Nm (7.5 ftlb.) to 15 Nm (11.0 ftlb.).
23. Fill the cooling system with a mixture of anti-freeze protection and water (mix ratio 50:50) and bleed.
24. Check the cooling system for leaks.
25. Fit the underside panel into place again.
26. Perform an extended test drive with the vehicle and subsequently check the coolant level.