SECTION 22: HEATING AND AIR CONDITIONING
28
DOB 2490-2789 | X3-45 Commuter PA1605 Maintenance Manual (Final Version – Rev.2 April 2016)
Blown Head Gaskets
Symptom:
*
Loss of unit capacity at low temperature.
*
Even cylinder head temperature.
Cause:
*
Improperly torqued cylinder head bolts.
*
Improperly positioned gasket at assembly.
*
Warped
cylinder
head.
*
Severe liquid refrigerant floodback.
Blown Valve Plate Gaskets
Symptom:
*
Loss of unit capacity at medium and low
temperatures.
*
Very hot cylinder head surface.
*
Higher than normal suction pressure.
Cause:
*
Improperly torqued cylinder head bolts.
*
Severe liquid refrigerant floodback.
*
Oil slugging caused by an overcharge of oil
or flood starts.
*
Discharge valves not seated properly (liquid
drainback during shutdown).
Broken Suction Valves
Symptom:
*
Loss of unit capacity at all temperatures.
*
Compressor unable to pull extremely low
vacuum with suction shut-off valve
frontseated.
Cause:
*
Repeated liquid refrigerant floodback.
*
Flooded
starts.
*
Overcharge of oil.
*
Discharge valves not seated properly (liquid
drainback during shutdown).
*
Expansion valve not controlling properly.
Unloader Valve Stuck Open
Symptom:
*
Loss of unit capacity at all temperatures.
*
Higher than normal suction pressure.
*
Even cylinder head temperature.
Cause:
*
Unloader body stem bent.
*
Foreign material binding unloader plunger.
FIGURE 30: UNLOADER COIL ASSEMBLY
7.2 ELECTRO-MAGNETIC
CLUTCH
Refer to
Lang Electromagnetic clutch
mounting-dismounting
and
Bitzer
Maintenance Instruction kw-540-1
provided
with the technical publications in PDF format for
further details on electro-magnetic clutch
removal and installation.
7.3 EVAPORATOR
MOTOR
The evaporator motor is installed in the
evaporator compartment (L.H. side of vehicle)
(Figure 31). It is a 27.5 volt, 2 HP (1.5 kW) motor
which activates a double blower fan unit.
FIGURE 31: EVAPORATOR COMPARTMENT
22301_B
7.3.1 Removal
Set the battery master switch (Kissling
switch) to the OFF
position.
