Four Seasons
Heater Valve

Four Seasons 74005 HVAC Heater Control Valve

Brand Four Seasons 74005
Bypass? No
Description Vacuum Closes Non-Bypass Heater Valve
Hose Connector Quantity 2 Connectors
Material Plastic
O.E. Replacement? Yes
Opening B IN 0.625
Opening IN 0.625
Operation Type Cable
Style Non-Bypass
Type Heater Valves
Product line Heater Valve
Fits Acura · 5 vehicles

OE replacement. Direct-fit heater control valve for straightforward installation.

Vacuum closes. Non-bypass design helps regulate coolant flow reliably.

Plastic construction. Lightweight material resists corrosion in HVAC service.

Cross-references Carlson H861, Four Seasons 74005 and 79700SD4A01 for the same application. See all 12.

$49.92Free shipping
In stock · usually ships same day before 1pm CST
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Order total $49.92
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Free returns within 60 days if it doesn't fit when fitment is verified.

Four Seasons 74005 Heater Valve Overview

The Four Seasons Heater Valve 74005 is an OE replacement HVAC heater control valve for vacuum-operated heating systems. It uses a cable operation type, a non-bypass design, and a plastic body with two hose connectors sized at 0.625 in. This part is a direct-fit option for 1986-1990 Acura Legend models with a vacuum operated heater valve setup.

Key Features

  • Brand: Four Seasons Heater Valve
  • Part number: 74005
  • HVAC heater control valve for temperature control systems
  • Vacuum closes non-bypass heater valve design
  • OE replacement construction
  • Plastic housing with 2 hose connectors
  • 0.625 in openings
  • Cable operation type
  • Compatible with 1986-1990 Acura Legend, vacuum operated heater valve applications

Product Details

Four Seasons 74005 is built for HVAC temperature control service where coolant flow through the heater circuit must be regulated by a vacuum-closing, non-bypass valve. The OE replacement design supports factory-style fitment and function on Acura Legend models from 1986 through 1990. If you are replacing a worn or leaking heater valve on an Acura Legend, this Four Seasons heater valve 74005 provides the correct connector layout and opening size for the listed application.

This part cross-references Carlson H861 for the same application.

Common Problems This Part Can Address

  • Heater core flow that does not shut off when the temperature control is moved
  • Coolant leakage at the heater valve housing
  • Broken or sticking vacuum-operated heater valve operation
  • Loss of cabin temperature control on Acura Legend HVAC systems
  • Incorrect heater hose routing caused by a failed non-bypass valve

Installation Notes and Tips

Verify the vehicle uses a vacuum operated heater valve before installation. Match the hose connector size, opening diameter, and non-bypass configuration to the original part on the vehicle. Inspect heater hoses, clamps, and vacuum lines for wear before installing the new valve, and confirm proper cable and vacuum function after installation on the Acura Legend.

Quality Assurance

Four Seasons supplies HVAC temperature control components for OE-style replacement service, and this heater valve is listed as an OE replacement part for the specified application.

This part fits 5 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelPositionNotes
1990AcuraLegendN/AVacuum Operated; Heater Valve
1989AcuraLegendN/AVacuum Operated; Heater Valve
1988AcuraLegendN/AVacuum Operated; Heater Valve
1987AcuraLegendN/AVacuum Operated; Heater Valve
1986AcuraLegendN/AVacuum Operated; Heater Valve
Directly replaces or cross-references 12 part numbers
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.
Carlson — H861Four Seasons — 7400579700SD4A0179700SD4A0279700SD400379700SD401320847380105611174005CWK801056H74005HV1205