Four Seasons 91588 HVAC Heater Core

Four Seasons 91588 Heater Core for Mercury Cougar

The Four Seasons 91588 heater core is a copper/brass HVAC replacement built for heat transfer and OE-style fitment. It is listed for 1974-1976 Mercury Cougar models equipped with air conditioning, making it a direct-match option for restoring cabin heat performance.

Key Features

• Four Seasons Heater Core, part number 91588
• Copper core material with copper/brass heater core construction
• Core dimensions: 8 in. height, 6 in. width, 2 in. depth
• Tube size: 0.625 in. / 15.875 mm
• Meets or exceeds OEM requirements
• Compatible with 1974-1976 Mercury Cougar, A/C-equipped applications

Product Details

Four Seasons 91588 is part of the Heater Core line and is built as a copper/brass heater core for HVAC service. The compact 8 x 6 x 2 inch core size and 0.625 inch tubes support a direct replacement layout for the listed Mercury Cougar applications. This part cross-references Anchor 2263 and APDI 9010092 for the same application.

What It Helps Fix

• Weak or inconsistent cabin heat
• Coolant odor inside the vehicle
• Fogging caused by heater core leakage
• Loss of heater performance from a restricted core
• HVAC service needs on 1974-1976 Mercury Cougar models

Installation Notes

Verify the vehicle is a 1974-1976 Mercury Cougar with air conditioning before ordering. Match the core dimensions and tube size to the original unit, and inspect hoses, seals, and the HVAC case during replacement. Confirm pipe orientation and routing against the removed part, since adjustable pipe positioning is not listed for this heater core.

Quality Assurance

Four Seasons lists this heater core as meeting or exceeding OEM requirements. The copper/brass construction is intended for standard HVAC replacement service where accurate fit and dependable heat exchange are required.