Dayco
Curved Radiator Hose

Dayco 70865 Radiator Coolant Hose - Lower

Brand Dayco 70865
Position Lower
Material Epdm
Color Black
End 1 Inside Diameter 1 1/2
End 2 Inside Diameter 1 1/2
Contains Heat Shield N
Contains Protective Sleeve N
Hose Type Single i.d. hose
SAE Specification Sae j20r4 class d-1, sae j1684 type ec
Trunk Height 20 1/2
Product line Curved Radiator Hose
Fits Buick, Cadillac, Lexus, and Pontiac · 28 vehicles

Curved hose design. Helps route coolant smoothly through the cooling system.

EPDM construction. Built for dependable coolant transfer and heat resistance.

Single I.D. hose. A straightforward radiator coolant hose for replacement use.

Cross-references ACDelco 26042X, Atlas MC89 and Autopar RH401 for the same application. See all 19.

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Free returns within 60 days if it doesn't fit when fitment is verified.

Dayco 70865 Curved Radiator Hose

The Dayco 70865 curved radiator hose is a lower coolant hose built for specific applications that require a 1 1/2 in. inside diameter at both ends. Made from EPDM and finished in black, it is shaped to route coolant through the engine bay with the correct bend profile for the listed vehicles.

Compatible with select Lexus IS F, Cadillac DeVille, Cadillac Fleetwood, Buick LeSabre, Buick Riviera, Pontiac Bonneville, Pontiac Catalina, Pontiac Laurentian, and Pontiac Parisienne applications, this Dayco Curved Radiator Hose line focuses on direct-fit cooling system service. The 70865 part number is also referenced by several aftermarket and OE cross numbers for the same application.

Key Features

  • Dayco Curved Radiator Hose, part number 70865
  • EPDM construction for coolant hose service
  • Black finish
  • 1 1/2 in. inside diameter at both ends
  • Single I.D. hose design
  • Lower radiator hose position
  • Built to SAE J20R4 Class D-1 and SAE J1684 Type EC specifications

Product Details

This radiator coolant hose is shaped for lower hose routing in the listed applications, including 2008-2014 Lexus IS F, lower, and classic GM platforms such as 1982-1985 Cadillac Fleetwood, 1982-1984 Cadillac DeVille, 1977-1980 Buick LeSabre, 1977-1978 Buick Riviera, 1978-1980 Pontiac Bonneville, 1978-1980 Pontiac Catalina, 1980 Pontiac Laurentian, and 1980 Pontiac Parisienne. The EPDM rubber construction is suited to coolant circulation service, while the curved profile helps match the factory hose path. This part number 70865 cross-references Gates 21052 for the same application.

Common Cooling System Issues

  • Cracked or split lower radiator hose
  • Coolant leakage at the hose body
  • Softening or swelling from age and heat exposure
  • Poor hose routing after prior service
  • Restricted coolant flow from a deteriorated hose

Installation Notes and Tips

Verify the hose diameter, bend shape, and lower-position routing before installation. Inspect the radiator neck and engine connection points for corrosion, residue, or sharp edges that can affect sealing. Confirm the hose follows the original path without twisting so the curved profile seats correctly in the cooling system.

Quality Assurance

Dayco manufactures this hose to SAE J20R4 Class D-1 and SAE J1684 Type EC specifications for radiator coolant hose service. The 70865 is built as a direct replacement style hose for the listed vehicle applications.

This part fits 28 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelDrive TypeLitersCylindersFuel TypePositionNotes
2014LexusIS FLowerCurved Radiator Hose
2013LexusIS FLowerCurved Radiator Hose
2012LexusIS FLowerCurved Radiator Hose
2011LexusIS FLowerCurved Radiator Hose
2010LexusIS FLowerCurved Radiator Hose
2009LexusIS FLowerCurved Radiator Hose
2008LexusIS FLowerCurved Radiator Hose
1985CadillacFleetwoodRWD4.1LV8LowerCurved Radiator Hose
1984CadillacDeVille4.1LV8LowerCurved Radiator Hose
1984CadillacFleetwood4.1LV8LowerCurved Radiator Hose
1983CadillacDeVille4.1LV8LowerCurved Radiator Hose
1983CadillacFleetwood4.1LV8LowerCurved Radiator Hose
1982CadillacDeVille4.1LV8LowerCurved Radiator Hose
1982CadillacFleetwood4.1LV8LowerCurved Radiator Hose
1980BuickLeSabre5.7LV8LowerCurved Radiator Hose
1980PontiacBonneville5.7LV8LowerCurved Radiator Hose
1980PontiacCatalina5.7LV8LowerCurved Radiator Hose
1980PontiacLaurentian5.7LV8LowerCurved Radiator Hose
1980PontiacParisienne5.7LV8GASLowerCurved Radiator Hose
1979BuickLeSabre5.7LV8LowerCurved Radiator Hose
1979PontiacBonneville5.7LV8LowerCurved Radiator Hose
1979PontiacCatalina5.7LV8LowerCurved Radiator Hose
1978BuickLeSabre5.7LV8LowerCurved Radiator Hose
1978BuickRiviera5.7LV8LowerCurved Radiator Hose
1978PontiacBonneville5.7LV8LowerCurved Radiator Hose
1978PontiacCatalina5.7LV8LowerCurved Radiator Hose
1977BuickLeSabre5.7LV8LowerCurved Radiator Hose
1977BuickRiviera5.7LV8LowerCurved Radiator Hose
Directly replaces or cross-references 19 part numbers
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.
ACDelco — 26042XAtlas — MC89Autopar — RH401AutoZone — C1052CARQUEST — 21052Chrysler — 4266274Duralast — E70865Freshstart — 280Freshstart — 320Gates — 21052General Motors — 1252780General Motors — 1621380General Motors — 1624864Goodyear — 61250Goodyear — 61264NAPA — 7764Pirelli — 41250Pirelli — 41258Pirelli — 41264