Tribute 4WD L4-2.5L Hybrid (2009)
Heater Core: Testing and Inspection
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COMPONENT TEST - HEATER CORE - HYBRID
Heater Core
1. Inspect for evidence of coolant leakage at the heater hose to heater core attachments. A coolant leak in the heater hose could follow the heater core
tube to the heater core and appear as a leak in the heater core.
NOTE:Testing of returned heater cores reveals that a large percentage of heater cores are good and did not require the installation of a new heater core.
If a heater core leak is suspected, the heater core must be tested by following the plugged heater core component test before the heater core pressure test.
Carry out a system inspection by checking the heater system thoroughly as follows:
2. Check the integrity of the heater hose clamps.
NOTE:Spring-type clamps are installed as original equipment. Installation and overtightening of non-specified clamps can cause leakage at the heater
hose connection and damage the heater core.
Heater Core - Plugged
WARNING:Use extreme caution as the heater hoses will become too hot to handle and may cause serious burns if the system is working correctly.
Failure to follow this instruction may result in serious personal injury.
1. Check to see that the engine coolant is at the correct level.
2. Start the engine and turn on the heater.
3. When the engine coolant reaches operating temperature, feel the heater core inlet and outlet hose to see if they are hot.
4. If the outlet only is not hot:
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the heater core may have an air pocket.
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the heater core may be plugged.
5. If the inlet only is not hot, the thermostat may not be working correctly.
Heater Core - Pressure Test
Use the Pressure Tester to carry out the pressure test.
1. Drain the coolant from the cooling system.
NOTE:Due to space limitations, a bench test may be necessary for pressure testing.
2. Disconnect the heater hoses from the heater core.
3. Install a short piece of heater hose, approximately 101 mm (4 in) 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 Pressure Test Kit. Secure the heater
hoses, plug and adapter with hose clamps.
5. Attach the pump and gauge assembly from the Pressure Test Kit to the adapter.
6. Close the bleed valve at the base of the gauge. Pump 138 kPa (20 psi) of air pressure into the heater core.
