Cooling System, Flushing
Special tools and workshop equipment required
- Coolant Flushing and Filling Device: VAS531007
- Cooling System Tester - Directional Valve: VAS691005/5
- Hose Clip Pliers: VAS6362
- Shop Crane - Drip Tray: VAS6208
- Suction jet pump from the Cooling System Charge Kit: VAS6096
- Refractometer: T10007A
- Compressed air connector with 6 to 10 bar (87.02 to 145.03 psi) pressure
- Elbow Assembly Tool: T10118
Coolant has drained from flushing. Then the cooling system is filled with distilled water.
The cooling system is then flushed with approximately 19 liters (5 gallons) (of distilled water. Afterward the distilled water is replaced with coolant (mixture ratio of 50: 50).
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 30 liters (8 gallons) of distilled water
- From this 19 liters (5 gallons) will be required for flushing
- 11 liters (3 gallons) serve as security reserve and remain in the canister
- Reservoir with Coolant
- Fill with 30 liters (8 gallons) of coolant
- Freeze protection through approximately -36 °C (-32.8 °F), (mixture ratio 50: 50)
- From this 18 liters (4.8 gallons) will be required for flushing
- 12 liters (3 gallons) serve as security reserve and remain in the canister
- 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: VAS531007 after flushing
- Is connected between the valve block and the flushing hose -item ) COOLING SYSTEM, FLUSHING - List Item: Flushing Hoses
- Extraction Adapter
- Approximately 100 cm long
- Is connected to the suction hose -item ) COOLING SYSTEM, FLUSHING - List Item: Suction Hose in order to extract the coolant
Procedure:
-- Remove the engine cover. Refer to ENGINE COVER, REMOVING AND INSTALLING .
-- Drain the coolant. Refer to COOLANT, DRAINING AND FILLING .
-- With the coolant hose removed, pour approximately one liter distilled water in the coolant expansion tank.
-- Allow the coolant to drain into the Drip Tray.
-- Reconnect the removed coolant hoses.
Coolant Flushing and Filling Device: VAS531007 , Preparing:
-- Fill the container >>1<< with 30 liters (7.95 gallons) of distilled water.
-- Fill the container >>2<< with 30 liters (7.95 gallons) of coolant. Mixture ratio 50: 50 approximately -36 °C (-32.8 °F).
-- Drain the containers >>3<< and >>4<<.
-- Remove the valve block from the connector coupling on the equipment trolley,
-- Connect the Coolant Flushing and Filling Device: VAS531007 to the battery.
Coolant Flushing and Filling Device: 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 Cooling System Tester - Directional Valve: VAS691005/5 yet. The filling hose must first be bled.
-- Switch on the pump for the Coolant Flushing and Filling Device: 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.
Coolant Flushing and Filling Device: VAS531007 , Connecting:
-- Open the coolant reservoir cap -arrow-.
-- Install the test adapter -2- (Cooling System Tester - Directional Valve: 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 test adapter -2-.
-- Connect the suction jet pump -2- from the Cooling System Charge Kit: VAS6096 to the connector coupling -B- on the valve block -1-.
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 (-12.32 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 (-12.32 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 Coolant Flushing and Filling Device: VAS531007 also moves the distilled water into the coolant expansion tank.
-- Fill the cooling system until approximately 1 bar (14.5 psi) pressure is displayed.
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.
-- Remove the air filter housing. Refer to AIR FILTER HOUSING, REMOVING AND INSTALLING .
-- Release and disconnect the connector -1- from the Engine Coolant Temperature Sensor -G62- -3- with the ignition switched off.
When the connector is disconnected from the Engine Coolant Temperature Sensor -G62-, the Engine Temperature Control Actuator -N493- is opened when the engine starts and the radiator fan runs.
-- Temporarily install the air filter housing so that the space on the cylinder head remains accessible. The air filter housing can for example be laid on the battery.
-- Start the engine and let it run for one minute with increased speed. Then switch off the engine.
Cooling System, Flushing with Distilled Water
- Shut-off valve -A- closed, and shut-off valve -B- opened.
-- Remove the bleeder hose -2- from the coolant expansion tank -1-.
-- Connect the bleeder hose -2- from the coolant expansion tank with the flushing hose -1-.
-- Seal the connection on the coolant expansion tank using the plugs -3-. Secure the plug with a hose clamp.
-- Close the shut-off valve -B-.
The cooling system will be flushed. Pay attention to the fill level of the reservoir to maintain the flushing volume.
The engine runs at idle during the entire flushing procedure.
-- Start the engine and let it run in idle.
-- Set the heater temperature to "HI".
-- Press the AC button to turn off the A/C compressor.
1. Cylinder Block, Flushing with Distilled Water
-- Clamp off the bleeder hose for the heat exchanger and cylinder head with hose clamps.
-- Open the shut-off valve -A- on the valve block.
- Pump approximately nine liters (2.3 gallons) of distilled water through the engine
-- Closes the shut-off valve -A-.
2. Cylinder Head, Flushing with Distilled Water
-- Clamp off the bleeder hose for the heat exchanger and radiator with hose clamps.
-- Open the shut-off valve -A- on the valve block.
- Pump approximately two liters (2.11 quarts) of distilled water through the engine
-- Closes the shut-off valve -A-.
3. Heater Core for the Heater, Flushing with Distilled Water
-- Clamp off the radiator bleeder hose and cylinder head with hose clamps.
-- Open the shut-off valve -A- on the valve block.
- Pump approximately two liters (2.11 quarts) of distilled water through the engine
-- Closes the shut-off valve -A-.
4. Cooling System, Flushing Completely
-- Remove all hose clamps.
-- Open the shut-off valve -A- on the valve block.
- Pump approximately six liters (1.58 gallons) of distilled water through the engine
-- Closes the shut-off valve -A-.
Cooling System, Flushing with Coolant
-- Attach the suction hose -A- to the coolant container -2-.
1. Cylinder Block, Flushing with Coolant
-- Clamp off the bleeder hose for the heat exchanger and cylinder head with hose clamps.
-- Open the shut-off valve -A- on the valve block.
- Pump approximately five liters (5.28 quarts) of coolant through the engine
-- Closes the shut-off valve -A-.
2. Cylinder Head, Flushing with Coolant
-- Clamp off the bleeder hose for the heat exchanger and radiator with hose clamps.
-- Open the shut-off valve -A- on the valve block.
- Pump approximately five liters (5.28 quarts) of coolant through the engine
-- Closes the shut-off valve -A-.
3. Heater Core for the Heater, Flushing with Coolant
-- Clamp off the radiator bleeder hose and cylinder head with hose clamps.
-- Open the shut-off valve -A- on the valve block.
- Pump approximately two liters (2.11 quarts) of coolant through the engine
-- Closes the shut-off valve -A-.
4. Cooling System, Flushing Completely
-- Remove all hose clamps.
-- Open the shut-off valve -A- on the valve block.
- Pump approximately six liters (6.34 quart) of coolant through the engine
-- Closes the shut-off valve -A-.
The Flushing Procedure has Ended, Switch off the Pump and the Engine.
Coolant Flushing and Filling Device: VAS531007 , Removing:
-- Open the shut-off valve -B- and leave it open, so that the pressure in the cooling system reduces.
-- Remove the plug -3- from the coolant expansion tank and reconnect the bleeder hose -2-.
-- Seal the flushing hose -1- with the plug.
-- Remove the valve block -1- and test adapter -2-.
-- When a freeze protection up to -36 °C (-32.8 °F) is necessary, empty coolant expansion tank and fill with coolant concentrate.
The coolant can be extracted using the Coolant Flushing and Filling Device: VAS531007 . Refer to the information below.
-- The coolant must be at the >>weld seam<< -arrow-.
-- Reconnect the connector -1- to the Engine Coolant Temperature Sensor -G62- -3-.
-- Install the air filter housing.
-- There will be faults stored in the engine/motor control module DTC memory because the connectors were disconnected. Erase the DTC memory using the Vehicle Diagnostic Tester.
-- Close the coolant expansion tank cap until it locks into place.
-- Let the engine run in idle until the radiator fan switches on.
Coolant Level and Freeze Protection, Checking
-- If the freeze protection is not sufficient, extract the coolant from the coolant expansion tank. After filling with coolant concentrate adjust the correct freeze protection.
-- After filling with coolant concentrate, let run for approximately two minutes with raised speed and check the freeze protection again.
- Freeze protection must be assured down to minimum -25 °C (-13 °F) (in arctic climatic countries down to approximately -36 °C (-32.8 °F)). The freeze protection may only be increased, when stronger freeze protection is needed due to the climate. But only down to -48 °C (-54 °F), otherwise the effectiveness of the coolant decreases.
- When the engine is warm, the coolant must be at the >>weld seam<< -arrow-.
- When the engine is cold, the coolant must be approximately 5 mm -arrow- above the MAX mark.
The raised coolant level is necessary, since the coolant level can still sink from the ventilation process.
Coolant, Extracting
To extract the coolant use the extraction adapter -item ) COOLING SYSTEM, FLUSHING - List Item: Extraction Adapter.
-- Remove the suction hose -5- from the reservoir -2-.
-- Attach the extraction adapter -12- on the connector coupling from the suction hose -5-.
-- Switch on the pump -7- and open the shut-off valves -A and B- on the valve block -8-.
-- Extract the excess coolant using the extraction adapter -12-.
-- Connect the shut-off valves on the valve block and switch off the pump.
Coolant Flushing and Filling Device: VAS531007 , Cleaning:
If the coolant is in the viewing glass for a longer time, discoloration can occur. For this reason the viewing glass must be flushed with distilled water after the flushing procedure.
If the viewing glass is colored it must be cleaned with a nylon brush.
Use the cleaning adapters -item ) COOLING SYSTEM, FLUSHING - List Item: Cleaning Adapters to flush.
-- Connect the suction hose -5- to the reservoir -1- for distilled water.
-- Connect the flushing hose -10- on the cleaning adapters -9-. Connect the cleaning adapter -9- on the connector coupling -B- on the valve block -8-.
-- Open the shut-off valves -A and B- on the valve block -8-.
-- Switch on the pump -7- and pump distilled water through the hoses until the coolant in the viewing glass -6- is rinsed out.
-- Switch off the pump and close the shut-off valves.
-- Remove the cleaning adapters and seal the flushing hose again with plugs.