F 350 2WD Pickup V8-460 7.5L VIN G EFI (1997)
5. Attach Radiator/Heater Core Pressure Tester 014-R1069 or equivalent to the adapter. Close the bleed valve at the base of the gauge and pump
207 kPa (30 psi) of air pressure into the heater core.
6. Observe the pressure gauge for a minimum of three minutes. The pressure should not drop.
7. If the pressure does not drop, no leaks are indicated.
8. If the pressure drops, check the connections at the core for leaks. If the heater water hoses do not leak, remove the heater core from the vehicle.
Test the heater core.