Cooling System, Flushing: Notes
Special Tools And Workshop Equipment Required
- Coolant Flushing and Filling Device:VAS531007
- Cooling System Tester - Directional Valve:VAS691005/5
- Hose Clip Pliers:VAS6362
- Suction jet pump from the Cooling System Charge Kit:VAS6096
- Refractometer:T10007A
- Compressed air connector with 6.0 to 10 bar (87.02 to 145.03 psi) pressure
- Two hose clamps up to 25 mm
After Replacing The Following Components, The Cooling System Must Be Flushed:
- Cylinder Head
- Heater Core for the Heater
- Radiator
- Charge Air Cooling Circuit Cooler
- Intake Manifold with Charge Air Cooler
Old coolant is replaced with new coolant during the flushing procedure. This ensures the optimal surface protection of the new components.
The Cooling System Must Also Be Flushed If the Following Abnormalities Occur:
- The coolant has either developed a more intense color or become discolored.
- The coolant has an unnatural or unusual odor.
- Particles are visible in the coolant.
- Deposits have accumulated in the coolant expansion tank.
Coolant has drained from flushing. Then the cooling system is filled with distilled water.
The cooling system is then flushed with approximately 12 liters (12.68 quarts) of distilled water. Afterward the distilled water is replaced with coolant (mixture ratio of 50:50).
The cooling system is bled with the Vehicle Diagnostic Tester after changing the coolant.
Used coolant cannot be used again.
Brief instructions can be found here. Refer to QUICK REFERENCE GUIDE FOR FLUSHING COOLING SYSTEM . Only the essential procedural steps are listed in the quick reference guide. The brief instructions can be printed and checked off during the procedure.
Schematic Overview - :VAS531007 :
- Reservoir with Distilled Water
- Fill with 20 liters (21.13 qts) of distilled water
- Reservoir with Coolant
- Fill with at least 20 liters (21.13 qts) of coolant
- Freeze protection up to approximately -36 °C (-32.8 °F)
- Empty Container
- For used coolant
- Empty Container
- For used coolant
- Suction Hose
- Comes from the connection 2 on the viewing glass
- Viewing Glass
- If colored the viewing glass must be cleaned with a nylon brush
- Pump
- Cut-off pressure approximately 1.5 bar (21.75 psi)
- Valve Block
- With pressure gauge and shut-off valves
- Drain Hose
- Is connected to the valve block to reduce the pressure
- Flushing Hoses
- Is connected for flushing on the coolant expansion tank bleeder hose
- Comes from the connection 1 on the viewing glass
- If not used seal with plugs
- Plugs
- Hose Clamps
- Quantity 4
- Cleaning Adapters
- Approximately 15 cm long
- For cleaning the Coolant Flushing and Filling Device after flushing
- Is connected between the valve block and the flushing hose -item ) COOLING SYSTEM, FLUSHING - Flushing Hoses
- Extraction Adapter
- Approximately 100 cm long
- Is connected to the suction hose -item ) COOLING SYSTEM, FLUSHING - Suction Hose in order to extract the coolant
:VAS531007 , Preparing:
-- Fill the container >>1<< with at least 20 liters (21.13 qts) of distilled water.
-- Fill the container >>2<< with at least 20 liters (21.13 qts) of coolant. Mixture ratio 50:50 approximately -36 °C.
-- Drain the containers >>3<< and >>4<<.
-- Connect the battery charger.
-- Remove the valve block from the connector coupling on the equipment trolley,
-- Connect the :VAS531007 to the battery.
:VAS531007 , Bleeding:
-- Connect the suction hose -A- to the reservoir >>1<< with distilled water.
-- Connect the drain hose -arrow- on the connector coupling -B- on the valve block.
-- Close the shut-off valves -A- and -B-.
Do not connect the valve block to the :VAS691005/5 . The filling hose must first be bled.
-- Switch on the pump for the :VAS531007 .
-- Open the shut-off valve -A-.
-- Briefly open the shut-off valve -B- so that the filling hose is bled.
-- Close the shut-off valves -A- and -B- again.
:VAS531007 , Connecting:
-- Open the coolant reservoir cap -arrow-.
-- Install the :VAG1274/8 -2- (:VAS691005/5 ) on the coolant expansion tank -1-.
-- Remove the drain hose -arrow- from the connector coupling -B- on the valve block.
-- Connect the valve block -1- on the :VAG1274/8 -2-.
-- Connect the suction jet pump -2- from the :VAS6096 to the connector coupling -B- on the valve block -1-.
Vacuum can also be generated using the :VAS6096/2 instead of the suction jet pump. Connect the :VAS6096/2 and generate a vacuum. Refer to COOLANT, FILLING WITH Cooling System Charge Kit - Electric Vacuum Pump:VAS6096/2 .
Cooling System, Filling with Distilled Water
-- Place the drain hose -8- from the suction jet pump in a container.
-- Connect the pressure hose -6- on the suction jet pump -7-.
-- Open the shut-off valve -B- on the valve block -5-.
- A further vacuum is created in the cooling system by the suction jet pump. The needle on the pressure gauge must lower to a minimum -0.85 bar (12.33 psi).
-- Close the shut-off valve -B-.
-- Remove the pressure hose -6-.
-- Watch the pressure gauge. The needle on the pressure gauge must stay at a minimum -0.85 bar (12.33 psi). Only then is there enough vacuum in the coolant system for the filling.
Check the cooling system for leaks if the pressure drops.
The vacuum required depends on the pressure in the pressure air system.
-- >>Slowly<< open the shut-off valve -A-.
- The distilled water is extracted and the cooling system is filled via the vacuum in the cooling system. The pump for the :VAS531007 also moves the distilled water into the coolant expansion tank.
- After filling, the coolant expansion tank must be depressurized. Proceed as follows:
-- Close after filling the shut-off valve -A-.
-- Remove the suction jet pump -2- from the valve block -1-.
-- Connect the drain hose -arrow- to the connector coupling. Open the shut-off valve -B- and leave it open, so that the pressure in the cooling system reduces.