Man D 2840 LE 301, Repair Manual

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Draining and filling coolant
41
Note:
The turbocharger and the intercooler may not be bled when the coolant system is topped up.
Danger:
If, in an exceptional case, the coolant level has to be checked in an engine that has reached
operating temperature, first carefully turn the cap
Ä
with safety valve to the first stop, let off
pressure, then open carefully.
Note:
Do not open the cooling system when the engine is at operating temperature. This causes a
pressure loss in the cooling system.
If the cooling system has been opened when the engine is at operating temperature this can lead
to the alarm ”pressure in the expansion tank” when the engine is then put into operation and to a
reduction in the engine output.
Coolant pressure in the expansion tank is only built up again when the engine has cooled down.
The cooling system must therefore only be filled up when the engine is cold.
Caution:
When the cover is opened with working valves, there is a danger that it is not properly sealed when
closed again. The required overpressure is no longer set up in the cooling system. Premature
simmering and loss of coolant result. To avoid damage to the engine, this cover should as a
general rule only be opened in exceptional cases and then replaced by a new one.