Dayco 72978 Radiator Coolant Hose - Upper
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Dayco
 Curved Radiator Hose

Dayco 72978 Radiator Coolant Hose - Upper

Brand Dayco 72978
Position Upper
Material Epdm
Color Black
End 1 Inside Diameter 1 5/16
End 2 Inside Diameter 1 5/16
Contains Heat Shield N
Contains Protective Sleeve N
End 1 Outside Diameter 1 21/32
End 2 Outside Diameter 1 21/32
Hose Type Single i.d. hose
SAE Specification Sae j20r4 class d-1, sae j1684 type ec
Trunk Height 11
Product line Curved Radiator Hose
Fits INFINITI · 7 vehicles

EPDM construction. Resists heat and coolant exposure for dependable service.

Curved hose design. Routes coolant smoothly with a precise, formed fit.

SAE-rated hose. Built to meet J20R4 Class D-1 and J1684 Type EC standards.

$38.51Free shipping
In stock · usually ships same day before 1pm CST
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Order total $38.51
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Free returns within 60 days if it doesn't fit when fitment is verified.
Not what you need? See all Radiator Coolant Hose options

Dayco Curved Radiator Hose for INFINITI Q50

Dayco 72978 is a curved radiator coolant hose built for the upper cooling circuit on select 2014-2018 INFINITI Q50 models. Made from EPDM rubber and finished in black, it follows the OE-style routing needed for a clean, direct replacement in the engine bay.

Key Features

  • Fits 2014-2018 INFINITI Q50, upper
  • Curved radiator hose profile for the upper coolant path
  • EPDM construction for cooling-system service
  • Single I.D. hose with 1 5/16 in. inside diameter at both ends
  • Black exterior for a factory-style appearance
  • Built to SAE J20R4 Class D-1 and SAE J1684 Type EC specifications
  • Dayco part number 72978 for easy identification

Detailed Description

This Dayco curved radiator hose is engineered for the upper radiator connection on the INFINITI Q50, helping maintain proper coolant flow between engine components and the radiator. The EPDM rubber construction is suited for hot coolant service, while the curved shape supports the original hose routing found on 2014, 2015, 2016, 2017, and 2018 INFINITI Q50 applications. If you are searching for a 2014-2018 INFINITI Q50 upper radiator hose or Dayco 72978 replacement hose, this part matches the listed fitment and dimensions.

What It Is Used For

  • Replacing a cracked or aged upper radiator hose
  • Restoring coolant transfer in the engine cooling system
  • Correcting leaks at the upper hose connection points
  • Replacing a hose that has softened, swollen, or collapsed
  • Maintaining proper routing in the upper cooling circuit

Installation Notes and Tips

Verify the hose routing, end diameters, and position before installation. This hose has a 1 5/16 in. inside diameter at both ends and is listed for the upper position on the INFINITI Q50. Inspect the mating necks, clamps, and surrounding cooling-system components for wear or corrosion before installing the new hose. Dayco 72978 is a direct-fit style replacement for the listed application, so matching the vehicle year and position is important.

Quality Assurance

Dayco manufactures this hose to meet SAE J20R4 Class D-1 and SAE J1684 Type EC specifications, supporting consistent material and performance standards for cooling-system service.

Related reading

This part fits 7 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelLitersCylindersPositionNotes
2018INFINITIQ503.5LV6UpperCurved Radiator Hose
2017INFINITIQ503.5LV6UpperCurved Radiator Hose
2016INFINITIQ503.5LV6UpperCurved Radiator Hose
2015INFINITIQ503.5LV6UpperCurved Radiator Hose
2015INFINITIQ503.7LV6UpperCurved Radiator Hose
2014INFINITIQ503.5LV6UpperCurved Radiator Hose
2014INFINITIQ503.7LV6UpperCurved Radiator Hose