Coolant: Service and Repair
WM 193817 Draining and filling coolant
Tools
Preliminary work
1. Remove rear underbody cover. -> 519419 Removing and installing cover for rear underbody - section on "Removing" 519419 Removing and Installing Cover for Rear Underbody.
2. Remove the engine-compartment lid.
-> 557819 Removing and installing engine compartment lid .
Draining coolant
WARNING
Hot fluid
- Danger of scalding
-> Let the fluid cool down.
-> Wear personal protective gear.
WARNING
Caustic fluids
- Danger of chemical burns
-> Avoid contact with caustic fluid.
-> Wear personal protective gear.
-> Ensure that there is good ventilation.
-> If you do come into contact, wash off immediately with plenty of warm water and contact a doctor if necessary.
Information
- Check Henn coupling O-rings and replace them if necessary.
- Clean plug connection and coolant hoses before assembly.
- Coat O-rings and coolant hoses with Kluberplus Gel (Part No. 000.043.205.93).
- Remove stoppers before fitting the coolant lines and hoses.
Information
- The coolant reservoir is located in the engine compartment.
- Testing and inspection work is performed at the opening in the service tray.
- Filling and bleeding work are performed on the coolant reservoir.
Information
- The radiators must also be drained in order to drain all the coolant.
- This is not necessary for most tasks however.
1. Open the cap on the reservoir in the engine compartment.
2. Raise the vehicle and place a collecting pan underneath.
2.1. Secure the pan to the plate on the transmission jack V.A.G 1383 WE 1082 with a tension strap.
3. Unscrew the coolant drain plug (internal Torx, a/f 8) M14 x 1.5 -1- at the coolant regulator housing.
3.1. Replace sealing ring.
Coolant drain plug on thermostat housing
4. Pull off the large coolant (supply and return) hoses.
4.1. Remove moulded element -2- and open the line bracket -3-.
4.2. Remove the spring clamps -1- on the Henn couplings and pull the coolant hoses out of the coolant pipes. Collect emerging coolant.
4.3. Refit the spring clamps, check O-rings on the coolant hoses and replace them if necessary.
4.4. Refit the coolant hoses after draining the coolant. The Henn couplings must lock with an audible click.
4.5. Pull to check that the line is secure.
Coolant supply and return lines
5. Pull off the small coolant hoses (heater, heat exchanger).
5.1. Open the spring band clamps -1 to 3- using an assembly pliers Nr.72 Pos.2 and pull off the hoses.
5.2. Collect emerging coolant.
Spring band clamps for coolant hoses
Filling coolant
Filling coolant (includes bleeding the cooling system)
1. Fit the vehicle protective covers.
2. Protect the luggage compartment against soiling with a cover.
Information
The process of filling and bleeding the cooling system is performed using the special tool filling device 9696.
3. Screw cap adapter for coolant reservoir (K22) onto the tank and attach flexible extension (Fz100) to the cap.
3.1. Connect vacuum pressure gauge of filling device 9696 to the flexible extension. Ensure that both shut-off valves are closed (positioned at 90° with respect to flow direction).
Connecting adapter K22
4. Connect Venturi nozzle to the vacuum pressure gauge -arrow-.
Venturi nozzle on vacuum pressure gauge
Information
- The quantity of coolant available should exceed the amount required to fill the system by about two litres in order to prevent air being sucked in.
- An antifreeze content of -35 °C corresponds to a mixture of 50:50 (antifreeze: water).
5. Place a canister with a sufficient amount of coolant (antifreeze content approx. -35° Celsius) beside the vehicle close to the reservoir.
Information
- The bleeding process is completed more quickly if the canister is positioned at the same height as the coolant reservoir.
6. Screw the filler hose of the vacuum pressure gauge -5- onto the canister connection. Draw off the return line -6- into a second empty container.
6.1. Place the filling canister at the same height as the reservoir if possible.
Special canister filling tool
Information
- A hissing sound after connecting the compressed air supply is normal.
7. Connect the compressed air supply to the Venturi nozzle -arrow-.
Compressed air supply on Venturi nozzle
8. Bleed the filler hose.
8.1. Open both shut-off valves on the vacuum pressure gauge until the transparent filler hose has completely filled with coolant.
Shut-off valves open
9. Close left shut-off valve on the vacuum pressure gauge -arrow- and allow a vacuum to build up in the coolant circuit.
Left shut-off valve closed
Information
- If a vacuum does not build up, there is a leaking valve in the coolant circuit.
- Deformation of the rubber hoses of the cooling system is normal.
- When the pressure gauge pointer is in the green area of the display scale, a sufficient vacuum has been built up.
- After both shutoff valves on the vacuum pressure gauge have been closed and the compressed air supply has been disconnected, the vacuum must not drop. If the vacuum drops within approx. 30 seconds, there is a leak in the coolant circuit.
10. When sufficient vacuum has built up (pointer is in the green area), close the right shut-off valve and then unplug the compressed air supply.
Vacuum established (pointer in green area)
11. Open the left shut-off valve on the vacuum pressure gauge (right valve closed -arrow- ).
11.1. The cooling system is then filled.
Filling process: Left shut-off valve open - right valve (arrow) closed
12. The filling process is complete when the pressure gauge pointer is at zero.
12.1. Open the right shut-off valve.
13. Filling device 9696 can now be removed.
13.1. Unscrew cap K 22 on the coolant reservoir.
14. Check the engine coolant level at the service tray.
Coolant cap at service tray
14.1. Fill the coolant reservoir up to the maximum marking -MAX- if necessary and screw on the cap -1- of the reservoir securely (do not tilt).
Checking engine coolant level
Subsequent work
1. Start the engine and let it run until a coolant temperature of 80° Celsius is reached.
1.1. Check all connection and sealing points in the cooling system for leaks.
2. Install rear underbody cover. -> 519419 Removing and installing cover for rear underbody - section on "Installing" 519419 Removing and Installing Cover for Rear Underbody.
3. Check the coolant level at the service tray. Adjust the coolant level after the engine has cooled down if necessary.