Subaru Forester 2004 - Refrigerant Pressure with Manifold Gauge Set

AC-25
HVAC SYSTEM (HEATER, VENTILATOR AND A/C)
Refrigerant Pressure with Manifold Gauge Set
2. Refrigerant Pressure with Manifold Gauge Set
A: OPERATION
1) Place the vehicle in the shade and draftless condition.
2) Connect the manifold gauge set.
3) Open the front windows and close all doors.
4) Open the hood.
5) Increase the engine speed to 1,500 rpm.
6) Turn ON the A/C switch.
7) Turn the temperature control dial to MAX COOL.
8) Set the air inlet select switch to RECIRC position.
9) Turn the fan dial to HI.
10) Read the gauge.
Standard:
Low pressure: 127 — 196 kPa (1.3 — 2.0 kg/cm
2
, 18 — 28 psi)
High pressure: 1,471 — 1, 667 kPa (15 — 17 kg/cm
2
, 213 — 242 psi)
Ambient temperature: 30 — 35
° C (86 — 95 ° F)
B: INSPECTION
Symptom Probable cause Repair order
High-pressure side is unusually high.
• Defective condenser fan motor
• Clogged condenser fin
• Too much refrigerant
• Air inside the system
• Defective receiver dryer
• Replace the fan motor.
• Clean the condenser fin.
• Discharge refrigerant.
• Replace the receiver dryer.
• After reevacuating the receiver dryer,
charge appropriate amount of refriger-
ant.
High-pressure side is unusually low.
• Defective compressor
• Not enough refrigerant
• Clogged expansion valve
• Expansion valve frozen temporarily by
moisture
• Replace the compressor.
• Check for leaks.
• Replace the expansion valve.
• Fully evacuate the expansion valve.
Low-pressure side is unusually high.
• Defective compressor
• Defective expansion valve
• Too much refrigerant
• Replace the compressor.
• Replace the expansion valve.
• Discharge refrigerant.
Low-pressure side is unusually low.
• Not enough refrigerant
• Clogged expansion valve
• Expansion valve frozen temporarily by
moisture
• Saturated receiver dryer
• Check for leaks.
• Replace the expansion valve.
• Replace the receiver dryer.