17 00 039 Venting and Filling Cooling System With Vacuum Filling Unit
17 00 039 Venting/filling cooling system with vacuum filling unit (N74)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 partial quantities of coolant, replace these quantities which have been drained with new coolant.
Important!
You must protect the alternator against contamination by coolant during repair work on the cooling circuit.
Cover alternator with suitable materials.
Failure to comply with this procedure may result in an alternator malfunction.
Ordering information:
- Workshop equipment
- Workshop equipment catalogue
- No.- 81 39 152 473
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.
Illustration shows N63, procedure for N74 engine is 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 container
^ 4) Venturi nozzle
^ 5) Compressed air connection (maximum 6 bar)
^ 6) Outgoing-air hose (lead outgoing-air hose into a collecting container)
Prerequisites
^ Cooling system expansion tank must be empty.
^ There must be sufficiently premixed coolant in the filling unit container, 1 - 2 liters more than the vehicle filling capacity.
- Use only recommended coolant.
- Observe mixture ratio.
- Observe filling 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.
Application
Connect filling unit (1) with adapter (2) 17 0 113 to coolant 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. This bleeds the tyre inflation hose (1).
Shutoff valve (B) remains open (approx. 1 minute). Generate vacuum in cooling circuit. At a vacuum of -0.7 to -0.95 bar, the final vacuum is reached. Green scale in 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 close the Venturi nozzle (1).
The cooling system must maintain the vacuum for 30 sec. 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 event of leaks, check cooling system for tightness.
Important!
There must be sufficiently premixed coolant in the filling unit container, 1 - 2 liters more than the vehicle filling capacity.
Position the filling unit container at the same height as the coolant expansion tank.
Shutoff valve (B) remains closed during the filling procedure.
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, release remaining vacuum.
To do so, open shutoff valve (B).
Remove filling unit with adapter from expansion tank.
After filling the cooling system using the vacuum filling device, an additional bleeding procedure must be carried out!
Bleeding procedure for vehicles up to 03/2010 (heating pump in heater feed hose).
1. Add coolant up to upper edge of coolant filler neck. Coolant must not drop any further (no drop in coolant for approx. 1 minute.)
2. Connect the battery charger and switch on the ignition.
3. Set heater to maximum temperature. Press Automatic button (if present) and turn blower down to lowest stage (for a minimum period of 5 minutes).
4. Check coolant level and add coolant if necessary.
5. After switching off the heating pump, set the heating to min. temperature and switch off the blower.
6. Check cooling system for tightness.
7. Close off the coolant filler neck.
8. Start engine and run for approx. 1 min in high idle; to do so, switch on the air conditioning.
9. Then press on accelerator three times for 5 seconds each to rev the engine to approx. 4000 revolutions per minute, then let the vehicle run in idle for approx. 5 Min. more.
10. Warm up engine and activate map thermostat via diagnosis system.
11. 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).
Bleeding procedure for vehicles from 03/2010 (heating pump in heater return hose).
1. Add coolant up to upper edge of coolant filler neck. Coolant must not drop any further (no drop in coolant for approx. 1 minute.)
2. Connect the battery charger and switch on the ignition.
3. Check coolant level and add coolant if necessary.
4. Check cooling system for tightness.
5. Close off the coolant filler neck.
6. Set heater to maximum temperature. Press Automatic button (if present) and turn blower down to lowest stage (for a minimum period of 5 minutes).
7. Start the engine and let it run in high idle for approx. 1 min.
8. While doing so, press on accelerator three times for 5 seconds each to rev the engine to approx. 4000 revolutions per minute, then let the vehicle run in idle for approx. 5 Min. more.
9. Warm up engine and activate map thermostat via diagnosis system.
10. 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).
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.
Close coolant expansion tank.
Installation note:
Close sealing cap (1) until the arrow marks line up.
Check function of cooling system.
Check cooling system for tightness.