Workshop Manual

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A–27
Condition Possible cause Correction
Discharge (High Gauge) Pressure
Abnormally High
Condenser clogged or dirty. Clean the condenser fins
Ab
norma
ll
y
Hi
g
h
Cooling fan does not operate
properly.
Check the cooling fan operation.
Discharge (High Gauge) Pressure
Abnormally High.
Insufficient cooling.
Excessive refrigerant in system. Discharge and recover refrigerant.
Recharge to specified amount.
Discharge (High Gauge) Pressure
Abnormally High.
High pressure gauge drop. (After
stopping A/C, the pressure drops
approx. 196 kPa (28 psi) quickly)
Air in system. Evacuate and charge refrigerant
system.
Discharge (High Gauge) Pressure
Abnormally Low.
Insufficient cooling
Insufficient refrigerant in system. Check for leaks. Discharge and
recover the refrigerant. Recharge to
the specified amount.
Discharge (High Gauge) Pressure
Abnormally Low.
Low pressure gauge indicates
vacuum.
Clogged or defective expansion
valve.
Replace the expansion valve.
Discharge (High Gauge) Pressure
Abnormally Low.
Frost or dew on refrigerant line
before and after the receiver/drier or
expansion valve, and low pressure
gauge indicates vacuum.
Restriction caused by debris or
moisture in the receiver/drier.
Check system for restriction and
replace the receiver/drier.
Discharge (High Gauge) Pressure
Abnormally Low.
Compressor seal defective Repair or replace the compressor.
High and low pressure gauge
balanced quickly. (After turned off
A/C)
Poor compression due to a defective
compressor gasket.
Repair or replace the compressor.
Suction (Low Gauge) Pressure
Abnormally High.
Low pressure gauge (Low pressure
gauge is lowered after condenser is
cooled by water.)
Excessive refrigerant in system. Discharge and recover refrigerant
Recharge to specified amount.
Suction (Low Gauge) Pressure
Abnormally High.
Low pressure hose temperature.
(Low pressure hose temperature
around the com
p
ressor refrigerant
Unsatisfactory valve operation due
to defective temperature sensor of
expansion valve.
Replace the expansion valve.
around
the
com ressor
refrigerant
line connector is lower than around
evaporator.)
Expansion valve opens too long. Replace the expansion valve.
Suction (Low Gauge) Pressure
Abnormally High.
High and low pressure gauge
balanced quickly. (After turned off
A/C)
Compressor gasket is defective. Repair or replace the compressor.
Suction (Low Gauge) Pressure
Abnormally Low.
Insufficient cooling.
Insufficient refrigerant in system. Check for leaks. Discharge and
recover the refrigerant. Recharge to
specified amount.
Suction (Low Gauge) Pressure
Abnormally Low.
Frost on the expansion valve inlet
line
Expansion valve clogged. Replace the expansion valve.