898 / 1980
HVAC
845
HVAC
5
6
7
8
9
10
INSPECT CONDENSER
Is it okay?
VERIFYWHETHERMALFUNCTION IS
IN EXPANSION VALVE, RECEIVER/
DRIER AND REFRIGERANT LINES
OR ELSEWHERE
Are refrigerant’s high-pressure and low-
pressure values low?
VERIFYWHETHERMALFUNCTION IS
IN EXPANSION VALVE AND
RECEIVER/DRIER OR ELSEWHERE
Immediately after A/C compressor
operates, does refrigerant’s high-
pressure value momentarily rise to
correct value, then fall and stay below
it? ( Is there negative pressure on low-
pressure side?)
VERIFYWHETHERMALFUNCTION IS
IN EXPANSION VALVE OR
RECEIVER/DRIER
Turn A/C switch off and air conditioner
stop for 10 minutes.
Start engine.
Turn both A/C switch and fan switch
on.
Does malfunction occur after
compressor turn on?
VERIFY THAT EXPANSION VALE
HEAT-SENSING TUBE WITHIN
COOLING UNIT IS POSITIONED
SECURELYAND CORRECTLY
Is expansion valve heat-sensing tube
within cooling unit securely installed in
proper position?
INSPECT REFRIGERANT LINES
Inspect refrigerant lines
• Is piping free of damage and
cracks?
• Are piping connections free of oil
grime?
(Visual inspection)
• Are piping installation points on
condenser free of gas leakage?
Yes
Adjust refrigerant to specified amount.
( Excessive amount of refrigerant.)
No
Replace condenser, or repair and clean
condenser fins.
Yes
Go to next step
No
Go to step 14
Yes
Go to next step
No
Go to step 10.
Go to next step
Replace condenser and vacuum
refrigerant line more than 30 minutes by
vacuumpump, and refrigerant to specified
level. ( Since water has intermixed in
receiver/drier and it is saturated,
replacement is necessary.)
Replace expansion valve. ( Since valve
closes too much replacement is
necessary.)
Install heat-sensing tube securely in
proper position.
Go to next step
If piping or an A/C component is
damaged or cracked, replace it.
Go to next step
Yes
No
Yes
No
Yes
No
STEP INSPECTION
ACTION