Cleaning The Cooling System

Information 

• Only use the approved cleaning agent "Frostox R Spezial" (see PET). 
• Recommended mixture ratio for cleaning is 1:1 (cleaning agent/water). 
• Clean for about 10 minutes with the engine running (operating temperature), then drain the cleaning agent and flush with water. 
• Coolant hoses and sealing rings swell following long-term contact with engine oil (e.g. when oil and coolant are mixed), so perform visual inspections. 
• Always replace seals and O-rings in the cooling system following removal. 
• Open other required connection points on vehicles with auxiliary heating if necessary. 
• If further cleaning is required, repeat these steps. 
• Dispose of coolant additives, coolant and cleaning agents according to the respective, applicable national laws. 

1. Fill the cooling system with the cleaning agent mixture. The filling and bleeding procedure is performed in the same way as for filling coolant.

   See vehicle-specific specifications in the appropriate service information! 

2. Start the engine.
3. The cooling system is cleaned after warming up the engine and opening the coolant regulator while the engine is running (operating temperature).

   Leave the engine running for about 10 minutes after opening the coolant regulator. 

4. Switch off the engine.
5. Drain the cleaning agent at all drain positions and flush the system with water.
6. Repeat this cleaning process if necessary.
7. Visually inspect the coolant hoses and replace swollen and damaged hoses if necessary.
8. Replace seals and O-rings at the connection points.