Heater Core - Pressure Test

Use the Radiator/Heater Core Pressure Tester to carry out the pressure test.

NOTE: Due to space limitations, a bench test may be necessary for pressure testing.
1. Drain the coolant from the cooling system.
2. Disconnect the heater hoses from the heater core.
3. Install a short piece of heater hose, approximately 101 mm (4 inches) long on each heater core tube.
4. Fill the heater core and heater hoses with water and install Plug BT-7422-B and adapter BT-7422-A from the radiator/heater core pressure tester in the heater hose ends. Secure the heater hoses, plug and adapter with hose clamps.
   Fig 1: Securing Heater Hoses, Plug & Adapter With Hose Clamps

   Courtesy of FORD MOTOR CO.
5. Attach the pump and gauge assembly from the radiator/heater core pressure tester to the adapter.
6. Close the bleed valve at the base of the gauge. Pump 241 kPa (35 psi) of air pressure into the heater core.
7. Observe the pressure gauge for a minimum of three minutes.
8. If the pressure drops, check the heater hose connections to the core tubes for leaks. If the heater hoses do not leak, remove the heater core from the vehicle and carry out the bench test.