Four Seasons 91777 HVAC Heater Core

Reliable Heater Core Replacement for Ford, Mazda, and Mercury Vehicles

The Four Seasons Heater Core 91777 is designed to restore efficient heating performance in select Ford, Mazda, and Mercury models. Engineered with durable copper and brass materials, this heater core ensures consistent heat transfer and long-lasting operation.

• Core dimensions: 7-5/8 inches length, 6 inches width, 1-7/8 inches thickness
• Constructed from copper/brass for enhanced thermal conductivity
• Core depth of 1.875 inches and height of 7.625 inches
• Tube diameter: 0.625 inches (15.875 mm) for both inlet and outlet
• Meets or exceeds OEM specifications for reliable fit and function

Four Seasons Heater Core Product Line Overview

The Four Seasons Heater Core line focuses on delivering quality HVAC components that meet or exceed original equipment manufacturer standards. The 91777 heater core is part of this line, offering a copper/brass construction that provides durability and efficient heat exchange. This product line is engineered to maintain proper cabin heating performance in vehicles requiring precise fitment and reliable operation.

Detailed Product Description and Specifications

This HVAC heater core features a copper core material known for excellent heat transfer properties, ensuring your vehicle's heating system operates effectively. The core measures 7.625 inches in height, 6 inches in width, and 1.875 inches in depth, fitting precisely within the HVAC housing. Both inlet and outlet tubes have a diameter of 0.625 inches (15.875 mm), designed for secure hose connections without adjustable pipe positioning. The heater core style is copper/brass, providing corrosion resistance and durability under typical operating conditions.

Compatible Vehicles and Common Applications

This heater core is compatible with several Ford, Mazda, and Mercury models, including:

• Ford Escape and Tribute
• Mazda 626, MX-6, and Probe
• Mercury Mariner

It is designed to replace faulty or leaking heater cores that cause issues such as:

• Insufficient cabin heat during cold weather
• Coolant leaks inside the vehicle cabin
• Fogged or misted windows due to heater core leaks
• Overheating engine caused by coolant loss
• Unpleasant odors from leaking coolant

Installation Notes and Tips

When installing the Four Seasons Heater Core 91777, ensure the vehicle is compatible with the specified fitment models. Properly drain the cooling system before removal to avoid spills. Handle the copper/brass core carefully to prevent damage to the fins and tubes. Verify hose connections match the 0.625-inch tube diameter for a secure fit. Follow vehicle-specific service manuals for detailed removal and installation procedures.

Quality Assurance and Warranty Information

The Four Seasons Heater Core 91777 meets or exceeds OEM standards, ensuring reliable performance and durability. Manufactured with high-quality copper and brass materials, this heater core is built to withstand typical automotive operating conditions. Please refer to Four Seasons' warranty policy for coverage details.