Heater Core Bench Test
WARNING:
- Carbon monoxide gas is colorless, odorless and dangerous. If it is necessary to operate the engine with the vehicle in a closed area such as a garage, always use an exhaust collector to vent the exhaust gases outside the closed area. Failure to follow these instructions may result in personal injury.
NOTE:
- Testing of returned heater cores reveals that a large percentage of heater cores are good and did not require installation of a new heater core. If a heater core leak is suspected, the heater core must be tested by following the Heater Core Plugged Component Test, refer to HEATER CORE PLUGGED ; before the Heater Core Pressure Test, refer to HEATER CORE PRESSURE TEST . Carry out a system inspection by checking the heater system thoroughly as follows:
- Inspect for evidence of coolant leakage at the heater water hose to heater core attachments. A coolant leak in the heater water hose could follow the heater core tube to the heater core and appear as a leak in the heater core.CAUTION:
- Spring-type clamps are installed as original equipment. Installation and overtightening of non-specification clamps can cause leakage at the heater water hose connection and damage the heater core.
- Check the integrity of the heater water hose clamps.
- Remove the heater core from the vehicle. For additional information, refer to HEATER CORE .
- Drain all of the coolant from the heater core.
- Connect the 101 mm (4 inch) test heater water hoses with plug and adapter to the core tubes. Then connect the radiator/heater core pressure tester to the adapter.
- Apply 241 kPa (35 psi) of air pressure to the heater core. Submerge the heater core in water.
- If a leak is observed, install a new heater core, refer to HEATER CORE .