SECTION 05: COOLING SYSTEM
DOB 2490-2789 | X3-45 Commuter PA1605 Maintenance Manual (Final Version – Rev.2 April 2016)
11
7. 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 Fleet Charge Fully
Formulated universal formula antifreeze 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.
4. Add coolant up to the top of the sight glass.
5. Close the filler and pressure cap, then start
the engine and run it at fast idle until
reaching normal operating temperature.
Check for leaks.
NOTE
If for any reason, the coolant level drops below
the surge tank critically low level probe, the
Check Engine warning light will illuminate.
6. Stop engine and allow cooling.
7. Open the two heater line shutoff valves,
check the coolant level in the surge tank,
and then add as required.
CAUTION
Never pour cold coolant into a hot engine.
The sudden change in temperature may crack
the cylinder head or block.
If the entire system has been drained, redo the
previous steps while maintaining the two heater
line shutoff valves in the "Open" position. With
engine running, activate the driver's and central
heating systems to permit coolant circulation.
Complete the procedure by bleeding the heater
cores as explained in Section 22, under
“Bleeding Heating System”.
8. FLUSHING
If the cooling system is contaminated, flush the
cooling system as follows:
1. Drain the coolant from the engine.
2. Refill with clean water.
CAUTION
If the engine is hot, fill slowly to prevent rapid
cooling and distortion of the engine castings.
3. To thoroughly circulate the water, start and
run the engine for 15 minutes after the
thermostats have opened.
4. Fully
drain
system.
5. Refill with clean water and operate for 15
minutes after the thermostats have opened.
6. Stop engine and allow cooling.
7. Fully
drain
system.
Vehicles with coolant filters:
Fill with a 50/50-antifreeze/water solution.
Replace coolant filter as per the Lubrication and
Servicing Schedule in section 24 if required.
Dispose of spent fluids in an environmentally
responsible manner according to regulations in
effect in your area.
COOLING SYSTEM CAPACITY
(approximation)
Includes heating system: 24 US gal (91 liters)
8.1 COOLING SYSTEM DESCALERS
If the engine overheats and the fan belt tension,
coolant level and thermostat operation have
been found to be satisfactory, it may be
necessary to de-scale and flush the entire
cooling system.
Remove scale formation by using a reputable
and safe de-scaling solvent. Immediately after
using the de-scaling solvent, neutralize with a
neutralizing agent. It is important that product
directions be thoroughly read and followed.
After using the solvent and neutralizer, fully drain
the system, and then reverse flush the engine
and radiator (see
"Reverse Flushing" in this
section)
before filling the system with coolant
solution.
8.2 REVERSE FLUSHING
After the engine and radiator have been
thoroughly de-scaled, they should be reverse-
flushed. The water pump should be removed
