SECTION 22: HEATING AND AIR CONDITIONING
20
DOB 2490-2789 | X3-45 Commuter PA1605 Maintenance Manual (Final Version – Rev.2 April 2016)
no attempt should be made to correct the
leaks by tightening the connections beyond
the recommended torque. The O-rings are
designed to seal at the specified torque and
overtightening the connection does not
result in a satisfactory and permanently
sealed connection. The connection must be
disassembled and the cause of the leak
(damaged O-ring, defective lines, etc.)
corrected. Use new O-ring.
6.3 PUMPING
DOWN
This procedure is intended to reduce refrigerant
loss by isolating it in the compressor and
receiver tank, as well as in their connecting line,
in order to carry out repairs on other sections of
the air conditioning system (lines and
components).
NOTE
Once this pull down procedure has been
properly done, any component from the outlet
hose on the receiver tank, the filter-dryer, the
liquid solenoid valves, the evaporators, the
expansion valves, and all lines associated with
them can be serviced, then properly
evacuated.
It must be noted that there is STILL refrigerant
under pressure in the compressor, the
discharge lines, condenser, and receiver tank
and that these items cannot be serviced. To
service these items, it is required to recover
the refrigerant using a recovery unit.
CAUTION
The filter-dryer must be replaced after a
severe system failure or if a line in the
system has been opened over a prolonged
period of time. The line will then have to be
properly evacuated.
Best practice would be to replace the filter-
dryer each time a line is opened.
NOTE
Before attempting any repair between
compressor and receiver tank, use a recovery
unit to remove refrigerant from the system.
WARNING
To prevent any injury, when air conditioning
system must be opened, refer to previous
paragraph “PRECAUTIONS IN HANDLING
REFRIGERANT”.
NOTE
For this procedure to be done properly, it is
assumed the proper amount of refrigerant is in
the refrigeration system. If there is any doubt,
use a recovery unit to recover and weight the
amount of refrigerant in the system.
6.3.1 Procedure
1. Energize driver’s unit and passengers’ unit
(main HVAC system) section liquid solenoid
valve. To do so, connect male and female
connector housings of C24 together for the
passengers’ area (found on the HVAC
module in evaporator compartment) and
C44 for the driver's area (located on the
ceiling of the spare wheel compartment).
During normal use, both male and female
housings of connector C24 or C44 are kept
unplugged.
CAUTION
Connectors C24 & C44 must be disconnected
and their caps reinstalled after this procedure.
Leaving them connected will keep the driver’s,
passengers’ and parcel rack liquid solenoid
valves open, and result in battery draining if
the vehicle remains unused for several days.
FIGURE 20: COMPRESSOR SHUT-OFF VALVE
BACKSEATED POSITION (NORMAL OPERATING
POSITION)
