SECTION 05: COOLING SYSTEM
10
DOB 2490-2789 | X3-45 Commuter PA1605 Maintenance Manual (Final Version – Rev.2 April 2016)
6. DRAINING COOLING SYSTEM
Use the following procedures to drain the cooling
system partially or completely.
To drain engine and related components:
1. Stop engine and allow engine to cool. Close
both heater line shutoff valves.
On X3- 45 coaches, the valves are located in the
engine compartment. One is located under the
radiator fan drive mechanism support; another
valve is on the L.H. side of the engine
compartment in front of the radiator (Figure 14).
NOTE
Refer to section 22 under "Preheating
System" for information about preheater
access and heater line shutoff valve.
WARNING
Before proceeding with the following steps,
make sure the coolant has cooled down. The
sudden release of pressure from a heated
cooling system can result in loss of coolant
and possible personal injury (scalding) from
the hot liquid.
2. Close the shut-off valve on the coolant filter
mounting head and remove filter (perform
only if filter as to be replaced).
3. Open the shut-off valve on the coolant filter
mounting head and drain the coolant into a
suitable container. Close the shut-off valve.
4. Unscrew the surge tank pressure cap
counterclockwise, ¼ turn to let air enter the
system and permit the coolant to drain
completely from system.
5. Connect coolant extractor (Figure 15). 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 to follow these
precautions can cause serious illness or
death.
FIGURE 15: EXTRACTING COOLANT
05093
6. Open the radiator drain cock.
7. Remove the transmission oil cooler. Drain,
flush and inspect. Refer to Section 7,
“TRANSMISSION” for oil cooler
maintenance or preventive replacement.
CAUTION
Drain water pump completely before extended
storage to avoid possible water pump
damage.
If freezing weather is anticipated and the
engine is not protected with antifreeze, drain
the cooling system completely when 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 shut-off valves in the open
position; then follow the procedure under
“Draining Heating System”
in Section 22.
