Section 22: HEATING AND AIR CONDITIONING
PA1553
53
o Installation
a) Apply gasket cement to the line flanges,
put the two gaskets in place, and connect
water lines to the pump at the flange
connections. Position the pump and motor
assembly on the mounting bracket.
Position the mounting clamps over the
motor and secure with mounting bolts.
b) Connect electrical wiring to the pump
motor.
c) Open shutoff valve. Refer to "05
COOLING" under heading "Draining
Cooling System" for location of valves.
d) Fill the cooling system as previously
instructed in this section under "11.1.2
Filling Heating System", then bleed the
system as previously instructed in this
section under "11.1.3 Bleeding Heating
System".
11.2 SMALL HEATING SYSTEM
11.2.1 Draining Heating System
To drain the entire system, refer to Section 05,
“Cooling”. If only the driver’s HVAC unit heater
core must be drained, refer to the following
instructions.
o Draining Driver’s HVAC Unit Heater Core
a) Stop engine and allow engine coolant to
cool.
b) Locate the normally open hot water
pneumatic valve on the ceiling of the
spare wheel compartment (Fig. 62), move
the pilot-solenoid valve red tab to close
the valve.
WARNING
Before proceeding with the following steps,
check that coolant has cooled down.
c) Loosen hose clamp, install an appropriate
container to recover coolant, and
disconnect silicone hose from hot water
pneumatic valve.
d) From inside of vehicle, remove the two
finishing panels in front of unit. Remove
the three screws fixing the unit front panel.
Open the manual vent located inside the
HVAC unit, on the driver’s side (Fig. 52) to
ensure an efficient draining.
11.2.2 Filling Heating System
a) Ensure that the drain hose is reconnected
and the manual vent is closed.
b) Open the surge tank filler cap and slowly
fill the system to level of filler neck.
c) After initial filling, the water valve should
be open and the water recirculating pump
should be energized to assist in circulating
coolant through the heating system. To
perform this operation, start the engine,
switch on the HVAC control module and
set temperature to the maximum position
in order to request the heating mode.
d) When coolant level drops below the surge
tank filler neck, slowly fill the system to
level of filler neck.
e) Once the level has been stabilized,
replace cap.
11.2.3 Driver’s Hot Water Pneumatic Valve
Assembly
The small system driver’s hot water pneumatic
valve assembly is similar to the one installed in a
central heating system.
Refer to figure 62 for hot water pneumatic valve
location and to paragraph 11.1.5 for more
information.
11.2.4 Water Recirculating Pump
The small system water recirculating pump is
similar to the one installed in a central heating
system.
Refer to figure 62 for pump location and to
paragraph 11.1.7 for more information.