Piper Dakota Maintenance Manual page 132

CHART 2101. TROUBLESHOOTING (AIR CONDITIONER) (cont) .
Gauge Indication
Low suction pressure. (Evap-
orator not cold enough)
suction gauge may read a
vacuum indicating evap-
orator lacks refrigerant.
High suction pressure.
PIPER AIRCRAFT
PA-28-236
MAINTENANCE MANUAL
Probable Causes
Undercharge of refrigerant.
Moisture freezing in expan-
sion valve. Valve will show
frost. Expansion valve inlet
screen clogged. Inoperative
expansion valve. Valve stuck
closed or capillary bulb has
lost its charge.
Restriction anywhere in
liquid line, Restriction will
show frost.
Capillary bulb clamp loose
on suction line, Suction line
shows frost.
Expansion valve not closing.
Evaporator flooded. Suction
line frosted to compressor.
Compressor drive belt
slipping.
Magnetic clutch slipping.
Leaking or broken com-
pressor valves.
1F19
Remedy
Add refrigerant. Install new
dryer. Evacuate and recharge.
Remove screen. Clean with
solvent and replace. Warm
capillary by holding in hand.
If suction pressure does not
charge, replace expansion
valve.
Locate restriction and repair.
Clean contact surfaces of
suction line and cap bulb.
Tighten clamp.
Replace expansion valve.
Adjust belt tension.
Check electrical circuit for
correct voltage to clutch coil.
Clean clutch surfaces of oil.
Replace compressor.
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Page - 21 - 05
Reissued: August 1, 1986