17 .. ... Bleed and Fill the Cooling System For the Charge Air Cooler With the Vacuum Filling Unit
17 .. ... Bleed And Fill The Cooling System For The Charge Air Cooler With The Vacuum Filling Unit
Special tools required:
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.
IMPORTANT:
You must protect the alternator against contamination by coolant when carrying out repair work on the cooling circuit.
Cover alternator with suitable materials.
Failure to comply with this procedure may result in an alternator malfunction.
Note on ordering:
- Workshop equipment
- Workshop equipment catalogue
- No.-81 93 2 152 473
IMPORTANT:
Risk of slipping due to coolant on the floor.
Danger of injury.
Catch and dispose of emerging coolant in drip tray (1) and if necessary special tool 00 2 030 (universal hydraulic lifting equipment).
Recycling:
Observe country-specific waste disposal regulations.
Graphic shows the N63, procedure for other engines identical.
IMPORTANT:
Check all the coolant hoses before filling the cooling system with the vacuum filling unit.
If necessary, replace damaged and porous coolant hoses.
Vacuum filling unit consists of:
- 1) Filling unit with vacuum meter and shutoff valves
- 2) Filler hose
- 3) Coolant tank
- 4) Venturi air vent
- 5) Compressed air connection (max. 6 bar)
- 6) Outgoing-air hose (lead outgoing-air hose into a collecting vessel)
Prerequisites
- The expansion tank of the cooling system for the charge air cooler must be empty.
- There must be sufficiently premixed coolant in the filling unit container, 1 - 2 litres more than the vehicle filling capacity.
- Use only recommended coolant.
- Observe mixture ratio.
- Observe capacities.
- Position the filling unit container at the same height as the coolant expansion tank.
- Compressed air connection with 6 bar pressure present.
- Set heating to maximum temperature.
Use
Connect filling unit (1) with adapter (2) 17 0 109 to the charge air cooler expansion tank.
Shutoff valves (A) and (B) must be closed.
Connect venturi nozzle (1) to filling unit (2).
Connect compressed air (1) and open shutoff valve (B).
The venturi nozzle produces a flow noise.
Then open shutoff valve (A) until the filling hose (1) is free of bubbles. Close shutoff valve (A) again. The filling hose (1) is vented in this way.
Shutoff valve (B) remains open. Generate vacuum in cooling cycle for approx. 1 minute. The end vacuum is reached at a vacuum of -0.7 to -0.95 bar. Green scale on the vacuum meter.
NOTE: The coolant hoses contract during vacuum build-up.
Then close shutoff valve (B) again.
Both shutoff valves (A) and (B) must be closed. Then seal Venturi nozzle (1).
The cooling system must hold the vacuum for 30 seconds. If the needle in the vacuum meter falls, this indicates a leak in the cooling system.
If the vacuum remains constant, proceed with filling.
In the event of a leak, check the cooling system for the charge air cooler for leaks.
IMPORTANT:
There must be sufficiently premixed coolant in the filling unit container, 1 - 2 litres more than the vehicle filling capacity.
Position the filling unit container at the same height as the coolant expansion tank.
Shut-off valve (B) remains closed during the filling process.
To fill the cooling system, open shutoff valve (A) to filling unit container.
Coolant is now added.
The filling procedure is finished when the needle in the vacuum meter is at 0 bar or no longer falls.
If necessary, reduce remaining vacuum. Open shutoff valve (B) to do so.
Remove filling unit with adapter from expansion tank.
After filling the cooling system for the charge air cooler, the cooling circuit must be bled.
NOTE:
Do not leave the coolant expansion tank sealing cap open during the bleeding procedure.
1. Top coolant up to the upper edge of the expansion tank. Coolant level may not drop further. No drop in coolant for approx. 1 minute.
2. Connect battery charger.
3. Switch the ignition on.
4. Set heating to maximum temperature. Press Automatic button. Then set the blower to the lowest speed.
5. Press accelerator pedal for 15 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.
7. Refill expansion tank up to top edge immediately after drawing off until empty.
8. Adjust expansion tank to maximum level at end of bleeding procedure.
9. Check cooling system for leaks.
10. Close expansion tank.
11. If the venting procedure has to be carried out again, allow DME to drop completely (ignition key removed for approx. 3 minutes), then repeat from Point 5.
Adjust coolant level to max.
Close charge air cooler expansion tank.
Check cooling system for charge air cooler for leaks.