Expedition 2WD V8-281 4.6L VIN W EFI (1997)
Heater Core: Testing and Inspection
Digital Multimeter
Set, A/C Fittings
R-134a Automatic Calibration Halogen Leak Detector
Radiator/Heater Core Pressure Tester
Special Tools
HEATER CORE
WARNING: CARBON MONOXIDE 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.
NOTE: Testing of returned heater cores reveals that a large percentage of heater cores are good and should not have been replaced. If a heater
core leak is suspected, the heater core should be tested as per Plugged Heater Core procedures before pressure testing the heater core. Perform a
system inspection by checking the heater system thoroughly as follows:
1. 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.
2. Check the integrity of the heater water hose clamps.
3. Spring-type clamps are installed as original equipment. Use of non-specification clamps can cause leakage at the heater water hose connection
