High (Discharge) Pressure | Low (Suction) Pressure | Component — Causes |
|---|---|---|
Incorrect clutch air-gap Suction accumulator — refrigerant oil bleed hose plugged Refrigerant leaks | ||
a Low pressure reading will be normal to high if restriction is downstream of service access valve. b Low pressure reading will be low if restriction is upstream of service access valve.
Inspection
1. NOTE: Procedure 2 — Ambient Temperature Above 38°C (100°F)
Run the engine until it reaches normal operating temperature.
2. Connect the air conditioning service unit to the refrigerant system.
3. Set temperature to (lowest possible temp setting) with the dual function disabled (if equipped). Manually set blower on HI. If the vehicle has a fresh air/recirc button, set it to FRESH. If the vehicle has an Air Conditioning (A/C) switch or compressor on switch, set it to Air Conditioning (A/C) ON.
4. Open all vehicle windows and leave the hood open for the test. Open the rear hatch and/or rear doors (if equipped).
5. Confirm the compressor is operating and the engine cooling fan(s) are operating or engaged. Allow the vehicle to idle until the suction (low-side) and discharge (high-side) pressures are stable or fluctuate in a range that repeats.
6. Record the ambient (shop) temperature.
7. Record the discharge pressure. If the pressure is fluctuating, record the average value.
8. Determine if the discharge pressure falls within the normal operating limits using the Normal Refrigerant Discharge Pressures 38 - 49°C (100 - 120°F) Ambient (15 - 40% Relative Humidity) chart below.
9. Record the suction pressure. If the pressure is fluctuating, record the average value.
2016 Mustang workshop publication supplied to Mustang Atlas. Original technical text and illustrations; HTML formatting by Mustang Atlas. Source page numbering is retained for traceability. Follow the configuration, revision, warnings, and cross-references in the material. About this edition.