Four Seasons 91593 HVAC Heater Core

Four Seasons 91593 Heater Core Overview

The Four Seasons 91593 heater core is a copper/brass HVAC heater core built for direct replacement service in the heating system. It is specified for the 1971 Mercury Montego with air conditioning and is engineered to meet or exceed OEM requirements for fit and function.

Four Seasons Heater Core line components are focused on restoring cabin heat performance with application-specific dimensions and materials. This 91593 heater core uses a copper core material and a copper/brass style construction for service in the HVAC case.

Key Features

• Part number: 91593
• Brand: Four Seasons Heater Core
• Copper core material with copper/brass heater core style
• Core dimensions: 6 in. height, 6 in. width, 2 in. depth
• Tube size: 0.625 in. / 15.875 mm on both connections
• Meets or exceeds OEM specifications
• Adjustable pipe positioning: No

Detailed Product Description

This Four Seasons 91593 heater core is a direct-fit HVAC heater core for the 1971 Mercury Montego, N/A position, with notes for vehicles equipped with air conditioning. The compact 6 x 6 x 2 inch core size and copper/brass construction support proper heat transfer and case fitment in the vehicle’s heater assembly. If you are replacing a leaking or restricted heater core in a 1971 Mercury Montego, this part number 91593 provides an OE-style service replacement built to match the application requirements.

This part cross-references Anchor 9035 for the same application.

What This Heater Core Helps Address

• Loss of cabin heat from a leaking or failed heater core
• Coolant odor or moisture inside the HVAC case area
• Restricted coolant flow through the heater circuit
• Uneven or weak heat output from the dash vents
• Replacement needs for a 1971 Mercury Montego with air conditioning

Installation Notes and Tips

Verify the heater core dimensions, tube size, and HVAC case layout before installation. Confirm the vehicle is a 1971 Mercury Montego with air conditioning and compare the original tube orientation and connection points to the new Four Seasons 91593 heater core. Drain the cooling system before removal, inspect hoses and seals, and flush the heater circuit if contamination is present.

Quality Assurance

Four Seasons lists this heater core as meeting or exceeding OEM requirements. The copper/brass construction and application-specific sizing support consistent replacement quality for HVAC service.