17 00 039 Venting cooling system and checking for watertightness (N20)
Open sealing cap only after engine has cooled down.
Electric coolant pump:
Follow notes for CARRYING OUT REPAIR WORK ON THE COOLING SYSTEM .
Lifetime coolant filling:
Never reuse used coolant.
When replacing and removing components which rely on the corrosion protection effect of the coolant, it is essential to change the coolant. The cooling system must therefore be drained and refilled.
In the case of other removal work involving the draining of part quantities of coolant, replace these quantities which have been drained with new coolant.
When refilling:
- Use only recommended COOLANT .
- Observe appropriate water/antifreeze mixture ratio.
- Observe CAPACITIES .
Perform filling operation slowly.
Adjust coolant level to maximum.
Close coolant expansion tank.
Installation note:
Close the sealing cap (1) until the arrows line up.
Adding coolant:
Fill cooling system with VACUUM FILLING DEVICE .
- Bleeder screw on the coolant expansion tank.
- Bleeder screw on transmission oil cooler (only for vehicles with automatic transmission).
- Bleeder screw on radiator return hose.
Overview of bleeder screws in vehicles without high speed package:
- Bleeder screw on the coolant expansion tank.
- Bleeder screw on transmission oil cooler (only for vehicles with automatic transmission).
- Bleeder screw on radiator return hose.
- Bleeder screw on additional radiator (only for vehicles with high speed package).
Overview of bleeder screws in vehicles with high speed package:
Venting cooling system:
- Fill cooling system using the vacuum filling device, after completing the filling procedure, remove the vacuum filling device.
- Overfill the expansion tank (to below the tank ventilation line).
- Open the bleeder screw (1) with the expansion tank open.
- Open the bleeder screw on transmission oil cooler (2) until coolant emerges without bubbles and then close it again. Tightening torque 17 10 7AZ
- Open the bleeder screw on additional radiator (4) until coolant emerges without bubbles and then close it again. Tightening torque 17 10 7AZ
- Open the bleeder screw on radiator return hose (3) until coolant emerges without bubbles and then close it again. Tightening torque 17 10 7AZ
- Close bleeder screw on expansion tank Tightening torque 17 10 7AZ
- Massage coolant hoses (supply and return radiator).
- Connect battery charger.
- Switch on ignition and low-beam headlight. Switch on the low-beam headlights to perform the bleeding procedure. If the low-beam headlights are not switched on, the ignition (Terminal 15) will switch off automatically after a certain period of time and interrupt the bleeding procedure.
- Set heater to maximum temperature and turn blower down to lowest speed.
- Press accelerator pedal for 10 seconds to floor. Engine must not be started.
- The bleeding procedure is started when the accelerator pedal is pressed and takes approx. 12 minutes. (Electric coolant pump was activated and shuts down automatically after approx. 12 min).
- Then adjust the filling level in the coolant expansion tank to maximum.
- CHECK COOLING SYSTEM FOR WATERTIGHTNESS.
- Close coolant expansion tank.
- After the bleeding procedure, let the engine run until it is warm and the electric fan starts running.
- If cooling system bleeding must be carried out again (e.g. if the cooling system is leaking), allow the Digital Motor Electronics to drop completely (remove the ignition key for approximately 3 min), then repeat from Section 3.
Installation note:
Close the sealing cap (1) until the arrows line up.