MTU 20V4000M93 series Operating Instructions Manual page 233

2. Connect a suitable pump with a hose to drain
valve (arrowed).
3. Pump coolant into engine at 0.5 bar minimum
until coolant emerges from the loosened un-
ions at the coolant distributor.
4. Tighten the union for coolant line at the cool-
ant distributor (→ Page 224).
5. Continue filling process until coolant emerges
from the loosened unions at the turbocharg-
ers.
6. Tighten the coolant line union at the turbo-
chargers (→ Page 224).
7. Open breather valve of expansion tank and
top up with coolant until level reaches the
overflow edge.
8. Check condition of breather valve and clean
sealing faces if required.
9. Start engine with open expansion tank
(→ Page 76) and operate it at idle.
10. Open vent points successively, starting at the
lowest point and proceeding upwards. Wait
until air no longer emerges from the vent
points and close them.
11. When coolant temperature is 40 °C (T-Cool-
ant), increase engine speed to 1,000 rpm for
approx. 2 minutes, then reduce engine speed
to idle speed.
12. With the engine running idle, top up the ex-
pansion tank with coolant until the level is at
the overflow edge.
13. Stop engine (→ Page 88) and remove hand
pump.
14. Start engine with open expansion tank and
run it up to nominal speed (full load).
15. Operate engine at idle for approx. 5 minutes
until coolant temperature is steady. Check
coolant level in expansion tank. If the level is
higher than 50%, close breather valve of ex-
pansion tank. If the coolant level in expansion
tank is less than 50%, stop engine
(→ Page 88) and fill coolant into expansion
tank until coolant level is at the overflow
edge.
16. Close breather valve on expansion tank and
briefly run up engine to full load.
17. Stop engine (→ Page 88).
18. Allow the engine to cool down, then top up
with coolant until coolant level is at the over-
flow edge. Close breather valve on expansion
tank.
MS150048/05E 2018-03 | Coolant Circuit, General, High-Temperature Circuit | 231