Heater Core - Failure/Leaks At Inlet Tube

9214ford01

Article No.
92-6-16

March 11, 1992


HEATER - CORE TANK - 7.5L - "CRACKING" AT INLET TUBE


LIGHT TRUCK: 1989-91 ECONOLINE


ISSUE: Heater core failure may occur on 7.5L vehicles with 50,000 to 70,000 miles (80,000-110,000 km) of service, due to the heater core tank "cracking" at the heater core inlet tube. The tank "cracking" is the result of cyclical pressurization of the inlet hose, which puts a highly repetitive side load on the tube.

ACTION: Install a heater coolant flow control valve. Refer to the following service procedure for details.


NOTE: TO ASSURE PROPER FUNCTION OF THE COOLANT FLOW CONTROLLER, IT MUST BE INSTALLED IN THE HEATER INLET HOSE, IN THE CORRECT LOCATION AND CORRECT DIRECTION IN THE HOSE.

1. Allow the engine to cool and follow all shop manual safety precautions and procedures regarding the engine cooling system.

2. Remove radiator cap and drain coolant from the system until the level is below the heater inlet hose fitting on the engine manifold.

3. Remove the heater inlet hose from the fitting on the intake manifold.

4. Cut the hose in two, approximately 2 inches from the end that attaches to the fitting on the intake manifold.

Figure 1:

5. Position the flow controller in the hose in the position shown in Figure 1. Make sure the arrow on the controller points in the direction of coolant flow (towards the heater core).

6. Use standard heater hose clamps to secure the controller in place.

7. Attach the hose to the fitting on the intake manifold and clamp it into place.

8. Refill the radiator and top it off, if necsssary.

9. Install the radiator cap.

10. Start the engine to pressurize the system. Operate the the system and check for coolant leaks.

PART NUMBER PART NAME CLASS

F1UZ-18D406-A Heater Coolant Flow Control C

OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: Eligible Under Basic Warranty
Coverage
OPERATION DESCRIPTION TIME
920616A Install - Coolant Flow 0.5 Hr.
Control
DEALER CODING
BASIC PART NO. CONDITION CODE
18D406 01
OASIS CODES: 208999, 402000