Dayco 72991 Radiator Coolant Hose - Lower

Dayco 72991 Curved Radiator Hose Overview

Dayco 72991 is a curved radiator coolant hose built for lower cooling-system routing on select INFINITI applications. It uses EPDM construction and a black finish to match common OE-style hose requirements for heat, coolant exposure, and underhood routing.

Compatible With 2009-2019 INFINITI FX35, FX37, M35h, M37, Q70, Q70L, and QX70 lower radiator hose applications, this hose is shaped for the lower coolant path where a curved profile is required. The Dayco curved radiator hose line focuses on direct-fit cooling-system replacement for specific vehicle platforms.

Key Features

• EPDM rubber construction for radiator coolant service
• Curved lower hose profile for application-specific routing
• 1 5/16 in. inside diameter at both ends
• 1 3/4 in. outside diameter at both ends
• Black finish for a clean OE-style appearance
• Meets SAE J20R4 Class D-1 and SAE J1684 Type EC specifications
• Dayco part number 72991 for catalog and service identification

Detailed Description

Dayco 72991 is a single I.D. radiator coolant hose made from EPDM, a material commonly used in cooling-system hoses for its resistance to coolant exposure and underhood temperatures. The hose is engineered as a curved lower radiator hose with matching 1 5/16-inch inside diameters on both ends, making it suitable for the specified INFINITI lower hose routing. Dayco 72991 is listed for 2009-2012 INFINITI FX35, 2013 INFINITI FX37, 2012-2013 INFINITI M35h, 2011-2013 INFINITI M37, 2014-2019 INFINITI Q70, 2015-2019 INFINITI Q70L, and 2014-2017 INFINITI QX70. If you are replacing a lower radiator hose on an INFINITI FX35, Q70, or QX70, this part number provides a direct reference for the correct curved hose configuration.

What It Helps Address

• Coolant leaks from a cracked or aged lower radiator hose
• Softening, swelling, or collapse in the lower coolant line
• Improper hose routing after cooling-system service
• Loss of coolant circulation caused by a damaged hose connection
• Maintenance replacement on INFINITI FX35, FX37, M35h, M37, Q70, Q70L, and QX70 lower hose applications

Installation Notes and Tips

Verify end diameters, hose routing, and lower radiator hose orientation before installation. Inspect the mating necks, clamps, and adjacent cooling-system components for wear or corrosion before installing Dayco 72991. Confirm the hose follows the original curved path without kinks or twist, and refill and bleed the cooling system according to the vehicle service procedure after installation.

Quality Assurance

Dayco 72991 is built to SAE J20R4 Class D-1 and SAE J1684 Type EC specifications, supporting standardized radiator hose performance requirements for the listed INFINITI applications. The Dayco curved radiator hose line is positioned for direct replacement use in cooling-system service.