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Four Seasons 74771 HVAC Heater Control Valve - Front
| Brand | Four Seasons 74771 |
|---|---|
| Position | Front |
| Description | Vacuum Closes Non-Bypass Heater Valve |
| Hose Connector Quantity | 2 Connectors |
| Material | Steel |
| O.E. Replacement? | Yes |
| Opening B IN | 0.625 |
| Opening B MM | 15.875 |
| Opening IN | 0.625 |
| Opening MM | 15.875 |
| Operation Type | Vacuum |
| Style | Non-Bypass |
| Type | Heater Valves |
| Product line | Heater Valve |
| Fits | Ford · 5 vehicles |
OE replacement. Vacuum-operated heater valve for direct-fit service.
Steel construction. Built for dependable performance in HVAC temperature control.
Non-bypass style. Controls coolant flow through the heater valve.
Cross-references Four Seasons 74771, Monroe Shocks & Struts 5966 and 155820 for the same application. See all 14.
Four Seasons 74771 Heater Valve Overview
The Four Seasons Heater Valve 74771 is an OE replacement HVAC heater control valve built for vacuum operation and non-bypass flow control. It uses a steel body with two hose connectors and a 0.625 in. (15.875 mm) opening for direct-fit service in the heating system.
Compatible with 1986-1990 Ford Aerostar front applications with a 2-port valve, this Four Seasons 74771 heater valve supports accurate coolant flow control for the cabin heater circuit. It is a practical choice when replacing a worn or leaking Ford Aerostar heater valve.
Key Features
- Four Seasons Heater Valve line, part number 74771
- Vacuum-operated HVAC heater control valve
- Non-bypass style for heater circuit flow control
- Steel construction for underhood durability
- Two hose connectors
- 0.625 in. / 15.875 mm opening
- OE replacement design
Product Details
This HVAC heater control valve is designed to regulate coolant flow through the heater core using vacuum actuation. The non-bypass configuration helps maintain proper heater circuit routing, while the steel housing supports long-term service in the engine bay. Four Seasons 74771 is listed for 1986-1990 Ford Aerostar, front, with a 2-port valve, making it a direct reference for Ford Aerostar heater valve replacement searches and HVAC temperature control repairs.
This part cross-references Monroe Shocks & Struts 5966 for the same application.
Common Repair Uses
- Heater valve leaking coolant
- No heat or inconsistent cabin heat
- Vacuum-controlled heater circuit not opening or closing correctly
- Restricted coolant flow through the heater core
- Worn OE-style HVAC temperature control valve replacement
Installation Notes
Verify the vehicle uses a vacuum-operated, non-bypass heater valve with two hose connections and a 0.625 in. opening before installation. Confirm hose routing, connector style, and front-position application on 1986-1990 Ford Aerostar models. Match the existing valve layout to the original HVAC system configuration for proper fitment.
Quality Assurance
Four Seasons supplies this heater valve as an OE replacement part for HVAC temperature control service. Part number 74771 is built to match the listed application and specifications for direct replacement use.
| Year | Make | Model | Position | Notes |
|---|---|---|---|---|
| 1990 | Ford | Aerostar | Front | w/ 2-Port Valve; Heater Valve |
| 1989 | Ford | Aerostar | Front | w/ 2-Port Valve; Heater Valve |
| 1988 | Ford | Aerostar | Front | w/ 2-Port Valve; Heater Valve |
| 1987 | Ford | Aerostar | Front | w/ 2-Port Valve; Heater Valve |
| 1986 | Ford | Aerostar | Front | w/ 2-Port Valve; Heater Valve |
| No rows match your filter. | ||||