Gauge indication Refrigerant cycle Probable cause Corrective action
High-pressure side is too low
and low-pressure side is too
high.
AC356A
High and low-pressure sides
become equal soon after com-
pressor operation stops.Compressor pressure operation
is improper.
¯
Damaged inside compressor
packings.Replace compressor.
No temperature difference
between high and low-pressure
sides.Compressor pressure operation
is improper.
¯
Damaged inside compressor
packings.Replace compressor.
Both high and low-pressure
sides are too low.
AC353A
+There is a big temperature
difference between receiver
drier outlet and inlet. Outlet
temperature is extremely low.
+Liquid tank inlet and expan-
sion valve are frosted.Liquid tank inside is clogged a
little.+Replace liquid tank.
+Check lubricant for contami-
nation.
+Temperature of expansion
valve inlet is extremely low
as compared with areas near
liquid tank.
+Expansion valve inlet may be
frosted.
+Temperature difference
occurs somewhere in high-
pressure side.High-pressure pipe located
between liquid tank and expan-
sion valve is clogged.+Check and repair malfunc-
tioning parts.
+Check lubricant for contami-
nation.
+Expansion valve and liquid
tank are warm or only cool
when touched.Low refrigerant charge.
¯
Leaking ®ttings or components.Check refrigerant for leaks.
Refer to ``Checking Refrigerant
Leaks'', HA-119.
There is a big temperature dif-
ference between expansion
valve inlet and outlet while the
valve itself is frosted.Expansion valve closes a little
compared with the speci®ca-
tion.
¯
j
1Improper expansion valve
adjustment.
j
2Malfunctioning thermal
valve.
j
3Outlet and inlet may be
clogged.+Remove foreign particles by
using compressed air.
+Check lubricant for contami-
nation.
An area of the low-pressure
pipe is colder than areas near
the evaporator outlet.Low-pressure pipe is clogged
or crushed.+Check and repair malfunc-
tioning parts.
+Check lubricant for contami-
nation.
Air ¯ow volume is not enough
or is too low.Compressor pressure operation
is improper.Replace compressor.
TROUBLE DIAGNOSESMANUAL
Trouble Diagnoses for Abnormal Pressure
(Cont'd)
HA-37
