Draining The Coolant Circuit; Coolant - Filling - Nanni N4.65 Operator's Manual

S08 MAINTENANCE

DRAINING THE COOLANT CIRCUIT

1. Stop the engine and remove the key from the panel.
2. Put a container along with a hose under the drain
plug (A) located at the bottom of the water cooling
box to collect coolant. Remove the top filler cap (B)
to ease draining flow.
3. Drain off all coolant. Empty the recovery container as
well as the hoses used in the process.
4. Insert a hose into the heat exchanger filler port. Rinse
with fresh water until water which flows from the
drain port is clean.
5. Reinstall the drain plug(s), secure them and fill with
new coolant as explained on next paragraph..

COOLANT - FILLING

Mix the anti-freeze with water in a clean container before
filling the heat exchanger. The coolant must be totally
free from dust. Fill the exchanger slowly not to introduce
air into the coolant system.
Refer to the chapter TECHNICAL DATA to know the
coolant capacity of the heat exchanger. For Keel Cooling
system or when using a water boiler, the coolant capacity
must be adapted according to the pipes length and the
tank capacity.
TO FILL THE COOLANT SYSTEM:
1. Check that the drain plug at bottom of exchanger (in
red) is properly tightened.
2. Open the vent in blue (red circle) on left side of the
picture.
3. Add coolant through the heat exchanger filler port
on top (in blue and red arrow) up to when coolant is
overflowing through circled blue vent.
4. Close and secure vent and cap.
5. Start the engine and let it operate few minutes at
idle. Stop the engine, wait few minutes and check
the coolant level in the heat exchanger and in the
expansion tank. Top up if necessary.
CAUTION !
If a boiler is connected to the engine, follow the filling
procedure given by the manufacturer of the boiler. If
the boiler is above the engine in the boat, first fill the
heat exchanger, the boiler, and top up with coolant the
recovery tank located above the boiler.
Make sure not to overfill the heat exchanger when filling
with coolant. If too much coolant has been added, drain
part of the coolant.
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