SL L4-1.9L DOHC VIN 7 (1992)
High Pressure Safety Valve HVAC: Description and Operation
Mounted in the front head is a high pressure relief valve. To protect the A/C system from high pressure in the event of an electrical control system failure
the valve will begin to open at about 530 psi. As system pressure is reduced the valve will reseat at about 425 psi. If the valve even opens it must be
replaced.
