F 150 2WD Pickup V6-4.2L VIN 2 (1997)
High Pressure Safety Valve HVAC: Description and Operation
An A/C compressor pressure relief valve is incorporated in the compressor's A/C manifold and tube to relieve unusually high refrigerant system
discharge pressure buildups (3241 kPa [470 psi] and above). This prevents damage to the A/C compressor and other system components and avoids
total refrigerant loss by closing after the excessive pressure has been relieved.
