Subaru Legacy 2004 Service Manual page 3381

Refrigerant Pressure with Manifold Gauge Set
2. Refrigerant Pressure with Manifold Gauge Set
A: PROCEDURE
1) Place the vehicle in the shade and windless condition.
2) Connect the manifold gauge set.
3) Open the front windows and close all doors.
4) Open the front hood.
5) Increase the engine to 1,500 rpm.
6) Turn on the A/C switch.
7) Turn the temperature control switch to MAX COOL.
8) Put in RECIRC position.
9) Turn the blower control switch to HI.
10) Read the gauge.
Standard:
Low pressure: 127 — 196 kPa (1.3 — 2.0 kg/cm
High pressure: 1,471 — 1,667 kPa (15 — 17 kg/cm
Ambient temperature: 30 — 35
B: INSPECTION
Symptom
High-pressure side is unusually high.
High-pressure side is unusually low.
Low-pressure side is unusually high.
Low-pressure side is unusually low.
2
, 18 — 28 psi)
2
, 213 — 242 psi)
! !
C (86 — 95 F)
Probable cause
• Defective condenser fan motor
• Clogged condenser fin
• Too much refrigerant
• Air inside the system
• Defective receiver dryer
• Defective compressor
• Not enough refrigerant
• Clogged expansion valve
• Expansion valve frozen temporarily by
moisture.
• Defective compressor
• Defective expansion valve
• Too much refrigerant
• Not enough refrigerant
• Clogged expansion valve
• Expansion valve frozen temporarily by
moisture.
• Saturated receiver dryer
AC-19
HVAC SYSTEM (HEATER, VENTILATOR AND A/C)
• Replace the fan motor.
• Clean the condenser fin.
• Discharge refrigerant.
• Replace the receiver dryer.
• After evacuating again, charge an
appropriate amount of refrigerant.
• Replace the compressor.
• Check for leaks.
• Replace the expansion valve.
• Fully evacuate the expansion valve.
• Replace the compressor.
• Replace the expansion valve.
• Discharge refrigerant.
• Check for leaks.
• Replace the expansion valve.
• Replace the receiver dryer.
Repair order