MTU 12 V 4000 M73 x Operating Instructions Manual page 195

Filling with coolant through fill-
er neck
1. Turn breather valve on filler neck of expan-
sion tank counterclockwise to first stop
and allow pressure to escape.
2. Continue to turn breather valve counter-
clockwise and remove.
3. Open vent points on intercooler, on coolant
cooler and on exhaust turbochargers
(→ Page 190).
4. Fill with coolant through filler neck on ex-
pansion tank.
5. When coolant emerges from the vent
points, close vent points one by one, pro-
ceeding from the lowest point upwards.
6. Fill expansion tank until overflow edge is
reached.
7. Start engine with expansion tank open
(→ Page 85) and leave running at idling
speed.
8. Open the vent points in sequence from bot-
tom to top until air stops emerging.
9. Close vent points.
10. Fill expansion tank until overflow edge is
reached.
11. When coolant temperature (T-Coolant) of
40 °C is reached, increase the engine
speed to 1000 rpm for approx. 2 minutes.
12. With the engine idling, fill expansion tank
until overflow edge is reached.
13. With the expansion tank open, run the en-
gine up to nominal speed (full load) under
load.
14. Leave the engine idling for approx. 5 mi-
nutes until the coolant temperature stabil-
izes.
15. Check coolant level in expansion tank:
• If coolant level is above 50%, close
breather valve.
• If coolant level is below 50%, stop en-
gine and fill expansion tank up to over-
flow edge.
16. Close breather valve on expansion tank
and run engine up to full load again.
17. After the engine has cooled down, top up
coolant up to overflow edge in expansion
tank.
18. Check proper condition of breather valve
and clean sealing faces if required.
19. Fit and close breather valve on expansion
tank.
MS150045/02E 2013-07 | Task Description | 195