Four Seasons 91662 HVAC Heater Core - Front

Four Seasons 91662 Heater Core Overview

The Four Seasons Heater Core 91662 is a specific-fit aluminum HVAC heater core built for direct replacement in select Toyota applications. It is sized for the factory heater box and meets or exceeds OEM requirements, making it a practical choice for restoring cabin heat and coolant-to-air heat transfer.

Compatible with 1985-1990 Toyota Pickup with Heavy Duty Heater and 1984-1988 Toyota 4Runner with Rear AC, this heater core is designed around the original vehicle layout. The Four Seasons heater core line focuses on replacement parts that match the application-specific dimensions needed for proper HVAC service.

Key Features

• Part number 91662 from Four Seasons Heater Core line
• Specific-fit aluminum heater core for direct replacement
• Aluminum core material for efficient heat transfer
• Core dimensions: 8-1/2 in. length, 5-3/4 in. width, 1-1/4 in. thickness
• Tube size: 0.625 in. / 15.875 mm on both connections
• Meets or exceeds OEM specifications
• Fixed pipe positioning for application-specific fitment

Detailed Description

Four Seasons 91662 is an aluminum HVAC heater core engineered for specific vehicle fitment and factory-style replacement. With an 8.500 in. core height, 5.750 in. core width, and 1.250 in. core depth, it is sized to align with the original heater assembly in the listed Toyota models. The aluminum construction supports efficient heat exchange, while the fixed tube layout helps maintain proper routing in the HVAC system. This part cross-references Spectra Premium 94662 and OSC 98662 for the same application.

For Toyota Pickup and Toyota 4Runner heater core replacement work, this part number 91662 provides a direct-fit option for vehicles equipped with the noted HVAC configurations. It is a straightforward choice when replacing a leaking, restricted, or heat-limited heater core in the cabin heating system.

What This Heater Core Can Address

• Loss of cabin heat in the Toyota Pickup or Toyota 4Runner HVAC system
• Coolant seepage from a deteriorated heater core
• Restricted coolant flow through the heater circuit
• Uneven or weak heat output from the dash vents
• Replacement needs after corrosion or internal blockage

Installation Notes and Tips

Verify the vehicle’s HVAC configuration before ordering: 1985-1990 Toyota Pickup with Heavy Duty Heater and 1984-1988 Toyota 4Runner with Rear AC. Confirm the core dimensions and tube orientation against the original unit before installation. Proper system flushing and inspection of hoses, clamps, and seals are recommended during heater core service to help protect the replacement part and restore consistent heater performance.

Quality Assurance

Four Seasons lists this heater core as meeting or exceeding OEM specifications, supporting a factory-style replacement standard for the listed Toyota applications. Part number 91662 is built for specific-fit service in the Toyota Pickup and Toyota 4Runner heater core applications noted above.