Filling Cooling System - PREVOST H3-41 Maintenance Manual

4. Unscrew the surge tank pressure cap of the
H3 Series vehicles counterclockwise, ¼ turn
to let air enter the system and permit the
coolant to drain completely from system. On
X3 Series, release the pressure using the
pressure release valve before removing the
pressure cap.
CAUTION
On X3 Series vehicles, never open the
surge tank pressure cap without making
sure first that the system is completely
depressurized. Coolant under pressure (hot
or not) may cause serious injuries and eyes
damages.
5. Connect coolant extractor (Figure 18). Use
coolant extractor to drain the coolant from
the engine. An alternate method is to drain
the coolant into a suitable container using
the drain hose.
DANGER
Coolant is toxic; risk of poisoning. Do not drink
coolant. Use proper hand protection when
handling. Keep coolant out of reach of children
and animals. Failure
precautions can cause serious illness or
death.
FIGURE 18: EXTRACTING COOLANT
to follow these
PA1621 Maintenance Manual All Series
SECTION 05: COOLING SYSTEM
6. Open the radiator drain cock.
7. Remove the transmission oil cooler. Drain,
flush and inspect. Refer to Section 7,
"TRANSMISSION"
maintenance or preventive replacement.
CAUTION
If freezing weather is anticipated and the
engine is not protected with antifreeze, drain
the cooling system completely when the
vehicle is not in use. Trapped water in the
cylinder block, radiator or other components
may freeze and expand resulting in damages.
Leave the drain plugs open until the cooling
system can be filled with coolant fluid. Do not
run engine with cooling system empty.
To drain the entire system, do the previous steps
while maintaining the shutoff valves in the open
position; follow procedure
Heating System" in Section 22.
8.

FILLING COOLING SYSTEM

If only the engine and related components were
drained, maintain the two heater line shutoff
valves in their closed position, then proceed as
follows:
1. Close radiator drain cock.
2. Open the shut-off valve on the coolant filter
mounting head.
3. Refill cooling system from the surge tank
filler cap inlet with the recommended
ethylene glycol-based antifreeze and water
solution of the required concentration using
the coolant extractor.
NOTE
Make sure the purge lines are properly
connected and not obstructed. The purge lines
(thermostat housing dome, radiator top tank,
transmission oil cooler or delivery line) are
required to ensure complete engine fill and
proper purging of air in the system.
NOTE
The coolant level should remain within two
inches of the tank filler neck.
|
Section 05 revised Feb 2019
for oil cooler
under
"Draining
19