Volvo has released a new cleaning method for oil in the cooling system.
If engine oil or automatic transmission fluid is found in the cooling system, the new method involves the use of a flush gun.
MATERIALS (see parts catalog in VIDA)
Expansion tank and cap
The root cause of oil contamination must be remedied prior to performing this cleaning procedure. Some examples include a defective engine oil cooler, defective radiator and/or defective cylinder head gasket. Once the root cause is remedied, use the following instructions in order to clean the cooling system.
- Special tool P/N 9814122 has been introduced for flushing the cooling system. The tool uses water and compressed air. After flushing, the thermostat, all rubber radiator hoses and the expansion tank with cover must be replaced. Note: The thermostat must be removed from the thermostat housing and the thermostat housing reinstalled for flushing to be effective.
- The hose that is connected to the thermostat housing must reach outside of the engine compartment. Use radiator hoses P/N 30776224 and 30761633 as tools. These are suitable for the different diameters on the outgoing connector on the thermostat housings and can be reused for multiple jobs.
- Drain the cooling system. Remove the thermostat and reinstall the thermostat housing. On most engines, the thermostat housing with thermostat is only available as a spare part. In these cases, the thermostat must be removed from the thermostat housing (this refers to vehicles with B6324S or B6304T2 engines). On C30/S40/V50 vehicles with B5254Sx/Tx engines, remove the thermostat, remove the rubber gasket from the thermostat, install the rubber gasket to the thermostat housing and reinstall the housing.
- Connect the cleaning gun to hose (hose 1 in illustration). Connect the water hose and compressed air to the cleaning gun. Connect a long hose to the thermostat housing, which extends outside of the engine compartment. Hot water is recommended. When flushing, the first 5.25 gallons must be flushed out into a container because the fluid contains coolant that must not be flushed out into the drainage network. Flushing can then occur over a flush plate with oil separation. Flush the cooling system for at least 10 minutes if hot water is used. If hot water is not available, extend the time to 20 minutes.
- After flushing, the thermostat, all rubber radiator hoses and the expansion tank with cover must be replaced.
Volvo offers a new cooling system flushing gun that works with a combination of water and compressed air.
Extra-long radiator hoses are required as flushing tools
For those thermostat housings with an integrated thermostat, the thermostat must be removed from the housing. This will later be replaced with a new housing/thermostat assembly.
For thermostat housings that feature a removable thermostat, remove the thermostat and reinstall the rubber gasket to the housing.
Using the flushing gun, flush the system for at least 10 minutes with hot water; or at least 20 minutes with cold water.