Bronco L6-300 4.9L VIN Y 1-bbl (1983)
Heater Core: Technical Service Bulletins
Heater Core - Leakage Diagnostic Tips
Article No. 85-8-2
HEATER CORE - LEAK - DIAGNOSTIC TIPS
FORD ALL
LINCOLN-MERCURY ALL
LIGHT TRUCK ALL
Good heater cores are being returned through the parts return system coded as leaking. Complaints of leaking may be caused by an inadequate seal
between the heater hose and the heater core tubes allowing coolant to follow the tube to the heater core, leak into the passenger compartment and appear
as a leaking heater core.
When diagnosing a suspect heater core leak, inspect the hose to heater core tube attachment to assure the connection is not leaking. If a leaking
connection is found, correct the leak. If the connection appears not to be leaking, leak test the heater core before removing it from the vehicle using the
following procedure:
HEATER CORE LEAK TEST
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 4 inches long) on each heater core tube.
Figure 1
4.
Fill the heater core and hoses with water and install plug BT-7422-B and adapter BT-7422-A from Rotunda model 021-00012 or equivalent in the
hose ends (Figure 1). Secure the hoses, plug and adapter with hose clamps.
