Four Seasons 74605 HVAC Heater Control Valve
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Four Seasons
 Heater Valve

Four Seasons 74605 HVAC Heater Control Valve

Brand Four Seasons 74605
Bypass? No
Description Vacuum Closes Non-Bypass Heater Valve
Hose Connector Quantity 2 Connectors
Material Steel
O.E. Replacement? Yes
Opening B IN 0.500
Opening B MM 12.700
Opening IN 0.625
Opening MM 15.875
Operation Type Vacuum
Style Non-Bypass
Type Heater Valves
Product line Heater Valve
Fits Buick, Chevrolet, GMC, Oldsmobile, and Pontiac · 181 vehicles

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

Vacuum closes. Non-bypass design controls coolant flow with vacuum operation.

Steel construction. Durable material built for dependable HVAC service.

Cross-references Four Seasons 20159, Four Seasons 74605 and Hayden 5908 for the same application. See all 24.

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Four Seasons 74605 Heater Valve Overview

The Four Seasons 74605 is an OE replacement HVAC heater control valve built for vacuum-operated heating systems. It uses a non-bypass, vacuum-closing design with two hose connectors and steel construction for direct-fit service on select GM vehicles.

Four Seasons Heater Valve line parts are built for temperature-control service where accurate coolant flow management matters. This 74605 heater valve is a vacuum-operated, non-bypass style with 5/8 in. and 1/2 in. openings, making it a practical replacement for original equipment layouts on Buick, Chevrolet, Oldsmobile, and Pontiac applications.

  • Brand: Four Seasons Heater Valve
  • Part Number: 74605
  • HVAC heater control valve for vacuum-operated systems
  • Vacuum closes non-bypass design
  • Steel construction
  • Two hose connectors
  • OE replacement style
  • Opening sizes: 0.625 in. and 0.500 in.

Detailed Product Description

Four Seasons 74605 is an HVAC heater control valve used to regulate heater core coolant flow in vehicles equipped with vacuum-actuated temperature control. The non-bypass configuration and vacuum-close operation match original-style heater valve layouts, while the steel body supports dependable service in underhood cooling and HVAC routing. This part cross-references Hayden 5908 for the same application.

Fits 1981 Buick Century, N/A; Fits 1981 Buick Regal, N/A; Fits 1980 Chevrolet Caprice, N/A; Fits 1980 Chevrolet Impala, N/A; Fits 1980 Oldsmobile 98, N/A; Fits 1980 Pontiac Catalina, N/A. Additional coverage includes select 1971-1980 Chevrolet El Camino, Monte Carlo, Malibu, Camaro, Corvette, and Nova applications, along with Buick, Oldsmobile, and Pontiac models listed in the fitment data.

Common Problems This Part Can Address

  • Heater core coolant flow that does not shut off correctly
  • Vacuum-controlled heater valve leakage
  • Loss of cabin temperature control
  • Sticking or worn original heater valve operation
  • Incorrect heater hose routing on OE-style systems

Installation Notes and Tips

Verify hose connector size, vacuum operation, and valve style before installation. This part uses a non-bypass layout, so confirm the vehicle’s original heater hose routing and port configuration match the 5/8 in. and 1/2 in. openings. Check for vacuum supply integrity and inspect heater hoses for age-related cracking before replacing the valve.

Quality Assurance

Four Seasons catalogs this part as an OE replacement heater valve for temperature-control service. The 74605 is listed with defined connector count, material, operation type, and fitment data to support accurate parts selection for the specified Buick, Chevrolet, Oldsmobile, and Pontiac applications.

Related reading

This part fits 181 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelBody TypeLitersCylindersFuel TypePositionNotes
1981BuickCenturySedan4.4LV8—N/Aw/o ECC; 1 End Threaded; Heater Valve
1981BuickRegalCoupe4.4LV8—N/Aw/o ECC; 1 End Threaded; Heater Valve
1980BuickCenturySedan5.0LV8—N/AHeater Valve
1980BuickCenturyCoupe5.0LV8—N/AHeater Valve
1980BuickLeSabreSedan5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1980BuickLeSabreCoupe5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1980BuickRegalCoupe5.0LV8—N/AHeater Valve
1980ChevroletCaprice—5.7LV8GASN/A5/8" Hose x 1/2" NPT; Heater Valve
1980ChevroletCaprice—5.0LV8GASN/A5/8" Hose x 1/2" NPT; Heater Valve
1980ChevroletCaprice—3.8LV6GASN/A5/8" Hose x 1/2" NPT; Heater Valve
1980ChevroletCaprice—4.4LV8GASN/A5/8" Hose x 1/2" NPT; Heater Valve
1980ChevroletEl Camino—5.0LV8—N/AHeater Valve
1980ChevroletEl Camino—3.8LV6—N/AHeater Valve
1980ChevroletEl Camino—4.4LV8—N/AHeater Valve
1980ChevroletImpala—5.7LV8GASN/A5/8" Hose x 1/2" NPT; Heater Valve
1980ChevroletImpala—5.0LV8GASN/A5/8" Hose x 1/2" NPT; Heater Valve
1980ChevroletImpala—3.8LV6GASN/A5/8" Hose x 1/2" NPT; Heater Valve
1980ChevroletImpala—4.4LV8GASN/A5/8" Hose x 1/2" NPT; Heater Valve
1980ChevroletMalibu—5.7LV8—N/AHeater Valve
1980ChevroletMalibu—5.0LV8—N/AHeater Valve
1980ChevroletMalibu—3.8LV6—N/AHeater Valve
1980ChevroletMalibu—4.4LV8—N/AHeater Valve
1980ChevroletMonte Carlo—5.0LV8—N/AHeater Valve
1980ChevroletMonte Carlo—3.8LV6—N/AHeater Valve
1980ChevroletMonte Carlo—4.4LV8—N/AHeater Valve
1980Oldsmobile98—5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1980OldsmobileCustom Cruiser————N/Aw/ 5/8" and 1/2" port sizes; Heater Valve
1980OldsmobileCutlass—5.0LV8—N/AHeater Valve
1980OldsmobileCutlass Cruiser—5.0LV8—N/AHeater Valve
1980OldsmobileCutlass Salon—5.0LV8—N/AHeater Valve
1980OldsmobileCutlass Supreme—5.0LV8—N/AHeater Valve
1980OldsmobileDelta 88—5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1980OldsmobileOmega————N/Aw/ 5/8" and 1/2" port sizes; Heater Valve
1980PontiacCatalina—4.4LV8—N/AHeater Valve
1979BuickCenturySedan5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1979BuickCenturyWagon5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1979BuickCenturyCoupe5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1979BuickCenturySedan5.0LV8—N/AHeater Valve
1979BuickCenturyCoupe5.0LV8—N/AHeater Valve
1979BuickLeSabreSedan5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1979BuickLeSabreCoupe5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1979BuickRegalCoupe5.0LV8—N/AHeater Valve
1979BuickRiviera—5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1979ChevroletCaprice—5.7LV8—N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1979ChevroletCaprice—5.0LV8—N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1979ChevroletEl Camino—5.7LV8—N/AHeater Valve
1979ChevroletEl Camino—5.0LV8—N/AHeater Valve
1979ChevroletEl Camino—4.4LV8—N/AHeater Valve
1979ChevroletEl Camino—3.3LV6—N/AHeater Valve
1979ChevroletImpala—5.7LV8—N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1979ChevroletImpala—5.0LV8—N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1979ChevroletMalibu—5.7LV8—N/AHeater Valve
1979ChevroletMalibu—5.0LV8—N/AHeater Valve
1979ChevroletMalibu—4.4LV8—N/AHeater Valve
1979ChevroletMalibu—3.3LV6—N/AHeater Valve
1979ChevroletMonte Carlo—5.0LV8—N/AHeater Valve
1979ChevroletMonte Carlo—4.4LV8—N/AHeater Valve
1979ChevroletMonte Carlo—3.8LV6—N/AHeater Valve
1979ChevroletMonte Carlo—3.3LV6—N/AHeater Valve
1979OldsmobileCutlass Salon————N/Aw/ 5/8" and 1/2" port sizes; Heater Valve
1979OldsmobileCutlass Supreme————N/Aw/ 5/8" and 1/2" port sizes; Heater Valve
1979OldsmobileOmega—5.7LV8—N/AHeater Valve
1979OldsmobileOmega—5.0LV8—N/AHeater Valve
1979PontiacGrand Am—5.0LV8—N/AHeater Valve
1979PontiacGrand Prix—5.0LV8—N/AHeater Valve
1979PontiacPhoenix—5.7LV8—N/AHeater Valve
1979PontiacPhoenix—5.0LV8—N/AHeater Valve
1978BuickCenturySedan5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1978BuickCenturyWagon5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1978BuickCenturyCoupe5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1978BuickCenturySedan5.0LV8—N/AHeater Valve
1978BuickCenturyCoupe5.0LV8—N/AHeater Valve
1978BuickLeSabreSedan5.0LV8—N/AHeater Valve
1978BuickLeSabreCoupe5.0LV8—N/AHeater Valve
1978BuickLeSabreSedan5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1978BuickLeSabreCoupe5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1978BuickLeSabreSedan6.6LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1978BuickLeSabreCoupe6.6LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1978BuickRegalCoupe5.0LV8—N/AHeater Valve
1978BuickRiviera————N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1978ChevroletCaprice—5.7LV8—N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1978ChevroletCaprice—5.0LV8—N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1978ChevroletEl Camino—5.7LV8—N/AHeater Valve
1978ChevroletEl Camino—5.0LV8—N/AHeater Valve
1978ChevroletEl Camino—3.3LV6—N/AHeater Valve
1978ChevroletImpala—5.7LV8—N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1978ChevroletImpala—5.0LV8—N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1978ChevroletMalibu—5.7LV8—N/AHeater Valve
1978ChevroletMalibu—5.0LV8—N/AHeater Valve
1978ChevroletMalibu—3.3LV6—N/AHeater Valve
1978ChevroletMonte Carlo—5.0LV8—N/AHeater Valve
1978ChevroletMonte Carlo—3.3LV6—N/AHeater Valve
1978OldsmobileCutlass Salon————N/Aw/ 5/8" and 1/2" port sizes; Heater Valve
1978OldsmobileCutlass Supreme————N/Aw/ 5/8" and 1/2" port sizes; Heater Valve
1978OldsmobileDelta 88—5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1978OldsmobileOmega—5.7LV8—N/AHeater Valve
1978OldsmobileOmega—5.0LV8—N/AHeater Valve
1978PontiacGrand Am—5.0LV8—N/AHeater Valve
1978PontiacGrand Prix—5.0LV8—N/AHeater Valve
1978PontiacPhoenix—5.7LV8—N/AHeater Valve
1978PontiacPhoenix—5.0LV8—N/AHeater Valve
1977BuickCenturySedan5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1977BuickCenturyWagon5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1977BuickCenturyCoupe5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1977BuickCenturySedan5.0LV8—N/AHeater Valve
1977BuickCenturyCoupe5.0LV8—N/AHeater Valve
1977BuickLeSabreSedan5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1977BuickLeSabreCoupe5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1977BuickLeSabreSedan6.6LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1977BuickLeSabreCoupe6.6LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1977BuickRegalSedan5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1977BuickRegalCoupe5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1977BuickRegalSedan5.0LV8—N/AHeater Valve
1977BuickRegalCoupe5.0LV8—N/AHeater Valve
1977BuickRiviera————N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1977ChevroletCaprice—5.7LV8—N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1977ChevroletCaprice—5.0LV8—N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1977ChevroletEl Camino—5.7LV8—N/AHeater Valve
1977ChevroletEl Camino—5.0LV8—N/AHeater Valve
1977ChevroletImpala—5.7LV8—N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1977ChevroletImpala—5.0LV8—N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1977ChevroletMalibu—5.7LV8—N/AHeater Valve
1977ChevroletMalibu—5.0LV8—N/AHeater Valve
1977ChevroletMonte Carlo————N/AHeater Valve
1977Oldsmobile98—5.7LV8—N/A2 Outlets; Right Angle Hose Connection; w/ Threads; Heater Valve
1977OldsmobileCustom Cruiser—5.7LV8—N/AHeater Valve
1977OldsmobileDelta 88—5.7LV8—N/AHeater Valve
1977PontiacPhoenix—5.7LV8—N/AHeater Valve
1977PontiacPhoenix—5.0LV8—N/AHeater Valve
1976ChevroletCaprice————N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1976ChevroletEl Camino—5.7LV8—N/AHeater Valve
1976ChevroletEl Camino—5.0LV8—N/AHeater Valve
1976ChevroletImpala————N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1976ChevroletMalibu—5.7LV8—N/AHeater Valve
1976ChevroletMalibu—5.0LV8—N/AHeater Valve
1976ChevroletMonte Carlo—5.7LV8—N/AHeater Valve
1976ChevroletMonte Carlo—5.0LV8—N/AHeater Valve
1975ChevroletCaprice————N/AHeater Valve
1975ChevroletEl Camino—6.6LV8—N/AHeater Valve
1975ChevroletEl Camino—5.7LV8—N/AHeater Valve
1975ChevroletEl Camino—7.4LV8—N/AHeater Valve
1975ChevroletImpala————N/AHeater Valve
1975ChevroletMalibu—6.6LV8—N/AHeater Valve
1975ChevroletMalibu—5.7LV8—N/AHeater Valve
1975ChevroletMalibu—7.4LV8—N/AHeater Valve
1975ChevroletMonte Carlo————N/AHeater Valve
1974ChevroletCaprice—6.6LV8—N/AHeater Valve
1974ChevroletCaprice—5.7LV8—N/AHeater Valve
1974ChevroletCaprice—7.4LV8—N/AHeater Valve
1974ChevroletEl Camino————N/AHeater Valve
1974ChevroletImpala—6.6LV8—N/AHeater Valve
1974ChevroletImpala—5.7LV8—N/AHeater Valve
1974ChevroletImpala—7.4LV8—N/AHeater Valve
1974ChevroletMalibu—6.6LV8—N/AHeater Valve
1974ChevroletMalibu—5.7LV8—N/AHeater Valve
1974ChevroletMalibu—7.4LV8—N/AHeater Valve
1974ChevroletMonte Carlo————N/AHeater Valve
1973ChevroletCaprice—6.6LV8—N/AHeater Valve
1973ChevroletCaprice—5.7LV8—N/AHeater Valve
1973ChevroletCaprice—7.4LV8—N/AHeater Valve
1973ChevroletEl Camino————N/AHeater Valve
1973ChevroletImpala—6.6LV8—N/AHeater Valve
1973ChevroletImpala—5.7LV8—N/AHeater Valve
1973ChevroletImpala—4.1LL6—N/AHeater Valve
1973ChevroletImpala—7.4LV8—N/AHeater Valve
1973ChevroletMalibu————N/AHeater Valve
1973ChevroletMonte Carlo————N/AHeater Valve
1972ChevroletCamaro————N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1972ChevroletCaprice————N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1972ChevroletCorvette————N/AHeater Valve
1972ChevroletEl Camino————N/AHeater Valve
1972ChevroletImpala————N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1972ChevroletMonte Carlo————N/AHeater Valve
1972ChevroletNova————N/AHeater Valve
1971ChevroletCamaro————N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1971ChevroletCaprice————N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1971ChevroletCorvette————N/AHeater Valve
1971ChevroletEl Camino————N/AHeater Valve
1971ChevroletImpala————N/ACompatible with vehicles equipped with air conditioning.; Heater Valve
1971ChevroletMonte Carlo————N/AHeater Valve
1971ChevroletNova————N/AHeater Valve
Directly replaces or cross-references 24 part numbers
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.
Four Seasons — 20159Four Seasons — 74605Hayden — 5908TYC — 30302UAC — HV1003151542502015522024614337017841000546341280103539920983992099399210046010386601038717460511174605VCWK801035H520H1944WV143