Four Seasons 74776 HVAC Heater Control Valve

Four Seasons Heater Valve 74776 Overview

Four Seasons Heater Valve 74776 is an OE replacement HVAC heater control valve built for vacuum-operated heater circuit control. It uses a bypass style design with a vacuum-close function to regulate coolant flow through the heater system on select Chrysler, Dodge, and Plymouth vehicles.

With four hose connectors and 0.625 in. (15.875 mm) openings, this Four Seasons heater valve is built for direct-fit service in applications such as the Dodge Daytona, Chrysler LeBaron, and Dodge Charger. The Four Seasons Heater Valve line focuses on replacement parts that match original equipment form and function for temperature control repairs.

Key Features

• Part number: 74776
• Vacuum-operated heater control valve
• Vacuum closes bypass heater valve design
• Bypass style with bypass function
• OE replacement construction
• Plastic housing
• Four hose connectors
• 0.625 in. / 15.875 mm openings

Detailed Description

Four Seasons 74776 is an HVAC heater control valve designed for vehicles that use vacuum actuation to manage heater coolant flow. The bypass configuration routes coolant through the heater circuit as required, then closes the bypass path when vacuum is applied. This helps restore proper heater control operation in systems that rely on an OE-style vacuum valve.

This part cross-references Hayden 5917 for the same application. It is listed for 1985-1988 Dodge 600, 1987-1988 Dodge Shadow, 1987-1988 Plymouth Sundance, 1985-1987 Chrysler Daytona, 1985-1987 Chrysler LeBaron, 1985-1987 Chrysler New Yorker, 1986-1987 Dodge Charger, 1985-1987 Dodge Daytona, 1985-1987 Dodge Lancer, 1985-1986 Chrysler Laser, and 1985 Dodge Charger from 10/22/84. The Four Seasons 74776 part number is also referenced in interchange listings for related aftermarket and OE-style applications.

Common Repair Symptoms

• Heater output stuck on hot or cold
• Coolant flow not switching correctly through the heater core
• Vacuum-controlled heater valve not responding
• Temperature control inconsistency in the cabin
• Leakage or deterioration at the heater valve housing

Installation Notes and Tips

Verify hose routing, connector count, and opening size before installation. Confirm the vehicle uses a vacuum-operated bypass heater valve and match the original hose layout on Chrysler, Dodge, and Plymouth applications. Inspect vacuum supply lines and heater hoses during replacement to ensure the new valve operates correctly after installation.

Quality Assurance

Four Seasons heater valves are OE replacement components built to match original-style HVAC control requirements for the listed applications. Confirm fitment by year, make, model, and heater valve configuration before ordering.