Four Seasons 90901 HVAC Heater Core - Front

Four Seasons 90901 Heater Core Overview

The Four Seasons 90901 heater core is an aluminum HVAC heater core built for direct replacement in select Ford, Lincoln, and Mercury applications. It is sized at 9-5/8 in. long, 6-1/8 in. wide, and 1-7/8 in. thick, with 5/8 in. inlet and outlet tubes for a precise fit in the heater box.

As part of the Four Seasons Heater Core line, this unit is made to meet or exceed OEM requirements and is engineered for dependable cabin heat restoration in vehicles such as the Ford F-150, Ford Expedition, and Lincoln Navigator.

Key Features

• Part number: 90901
• Aluminum heater core construction
• Core dimensions: 9-5/8 in. x 6-1/8 in. x 1-7/8 in.
• 5/8 in. tube size on both connections
• Meets or exceeds OEM specifications
• Direct-fit HVAC heater core for select Ford, Lincoln, and Mercury models

Detailed Product Description

The Four Seasons 90901 heater core is a replacement HVAC heater core designed around the listed dimensions and tube sizing for accurate installation in the heater assembly. Its aluminum core material supports efficient heat transfer, while the fixed pipe positioning helps maintain a consistent fit in the intended applications. This part number 90901 cross-references Dorman - Conduct-Tite 90901 for the same application.

Compatible With 2004-2008 Ford F-150, N/A; 2004-2008 Ford F-250, N/A; 2004-2008 Ford F-350, N/A; 2006-2008 Lincoln Mark LT, N/A; 2002-2006 Ford Expedition, Front; 2003-2006 Lincoln Navigator, Front; and 2005 Mercury Mountaineer, Front. For buyers searching for a Ford F-150 heater core, Lincoln Navigator heater core, or Ford Expedition front heater core, Four Seasons 90901 provides the specified fitment and dimensions.

Common Issues This Part May Address

• Weak or uneven cabin heat
• Coolant odor inside the vehicle
• Moisture or fogging from a leaking heater core
• Restricted heat output from corrosion or internal blockage
• HVAC performance loss in the heater circuit

Installation Notes and Tips

Verify core dimensions, tube diameter, and position before installation to confirm alignment with the heater box and hose routing. Because this is an HVAC heater core, access typically requires removal of interior trim or HVAC components depending on the vehicle. Flush the cooling system and inspect hoses, clamps, and coolant condition before completing the repair.

Quality Assurance

Four Seasons lists this heater core as meeting or exceeding OEM specifications, supporting a replacement choice built to the original application requirements. The Four Seasons Heater Core product line focuses on direct-fit HVAC replacement parts for vehicles that need restored cabin heat and proper coolant flow through the heater circuit.