Piper Arrow IV Turbo Maintenance Manual page 122

CHART 2101. TROUBLESHOOTING (AIR CONDITIONER) (cont)
Gauge Indication
Low suction pressure.
(Evaporator not cold enough)
suction gauge may
read a vacuum indicating
evaporator lacks re-
frigerant.
High suction pressure.
PIPER AIRCRAFT
PA-28RT-201 / 201T
MAINTENANCE MANUAL
Probable Causes
Undercharge of refrigerant.
Moisture freezing in ex-
pansion 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.
1F2
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.
21-00-02
Page 21-03
December 1, 1978