Leak /Pressure Test

INSPECTION
1. Inspect for visible evidence of coolant leakage at the hose to heater core attachments. A coolant leak at the hose could follow the heater core tube to the core and appear as a leak in the heater core.
2. Check the system for loose heater hose clamps. The clamps should be tightened to 1.81-2.49 Nm (16-22 in lb).
3. If leakage is found and the hose clamps are tight, check the heater core tubes for distortion. Severe distortion of the tubes could cause leakage at the hose connection.

PRESSURE TEST
1. Drain the coolant from the cooling system.
2. Disconnect the heater hoses from the heater core tubes.
3. Install a short piece of heater hose (approximately 101.6 mm (4 inches) long) on each heater core tube.






4. Fill the heater core and hoses with water and install plug BT-7422-B and adapter BT-7422-A from Rotunda model 21-0012 or equivalent in the hose ends. Secure the hoses, plug and adapter with hose clamps.

Rotunda 21-0012 With Heater Hose And Clamps:

5. Attach the pump and gauge assembly Rotunda model 21-0012 or equivalent to the adapter.

Rotunda 21-0012 Installed For Pressure Test:

6. Close the bleed valve at the base of the gauge and pump 207 kPa (30 psi) of air pressure into the heater core.
7. Observe the pressure gauge for a minimum of three minutes. The pressure should not drop.
8. If the pressure does not drop, no leaks are indicated.
9. If the pressure drops, check the hose connections to the core tubes for leaks. If the hoses do not leak, remove the heater core from the vehicle and bench test the heater core.

BENCH TEST
1. Drain all coolant from the heater core.

Heater Core Bench Test:

2. Connect the 101.6 mm (4 inch) test hoses with plug and adapter to the core tubes. Then, connect the air pump and gauge assembly to the adapter.
3. Apply 207 kPa (30 psi) of air pressure to the heater core with Rotunda model 021-0012 or equivalent, and submerge the core in water.
4. If a leak is observed, service or replace the heater core as necessary.