17 00 039 Venting Cooling System and Checking For Water Leaks

17 00 039 Bleed Cooling System And Check For Watertightness (N52T, N53, N55)







WARNING:
- Risk of scalding.
- Open sealing cap only after engine has cooled down.







IMPORTANT:
- Electric coolant pump.
- Follow notes for carrying out repair work on the cooling system.







IMPORTANT:
- 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.







Only when refilling.
Use only recommended coolant.
Observe mixture ratio.
Perform filling operation slowly.
Adjust coolant level to max.







Close coolant expansion tank.

Installation note:
Close the sealing cap (1) until the arrows line up.







IMPORTANT: The following bleeding procedure is necessary e.g. when a part is replaced in the cooling system or when the cooling system is refilled.







Adding coolant:
Cooling system must be filled with a vacuum filling unit only.
Use only recommended coolant.
Observe mixture ratio.







Venting cooling system:

NOTE:
Do not leave the coolant expansion tank sealing cap open during the bleeding procedure.

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.

1. Connect battery charger.
2. Switch the ignition on.
3. Switch on low-beam headlight.
4. Set heater to maximum temperature and turn blower down to lowest speed.
5. Press accelerator pedal for 10 seconds to floor. Engine must not be started.
6. The venting 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).
7. Then correct the fluid level in the coolant expansion tank to the maximum level.
8. Check cooling system on watertightness.
9. If bleeding needs to be repeated (e. g. if the cooling system is not tight), let the DME de-energise completely (keep the ignition key removed for approx. 3 minutes), then repeat beginning with point 2.







Close coolant expansion tank.

Installation note:
Close the sealing cap (1) until the arrows line up.







N53 only:
When the engine has cooled off, check the coolant level and adjust it to approx.
110 mm to 160 mm below the upper edge of the coolant filler neck (described further below in these instructions). Use a tape measure where appropriate.







N53 only:
Close coolant expansion tank.

Installation note:
Close the sealing cap (1) until the arrows line up.