Dayco 70399 Radiator Coolant Hose - Lower or Upper

Dayco Curved Radiator Hose for Jeep and Camaro

Dayco 70399 is a curved radiator coolant hose built for lower cooling-system routing on select Jeep and Chevrolet applications. Made from EPDM rubber in black, it uses a dual I.D. design to match the different end diameters required by the application.

This Dayco Curved Radiator Hose line is engineered for direct-fit cooling service on vehicles such as the Jeep Cherokee, Jeep Wrangler, Jeep Comanche, Jeep Wagoneer, and 1970-1972 Chevrolet Camaro. The hose follows the factory-style curved path to support proper coolant flow in lower radiator hose locations.

Key Features

• Part number: 70399
• Brand: Dayco Curved Radiator Hose
• Part type: radiator coolant hose
• EPDM construction for cooling-system use
• Black finish
• Dual I.D. hose design
• End inside diameters: 1 1/2 in. and 1 3/4 in.
• SAE J20R4 Class D-1 and SAE J1684 Type EC specification
• Lower hose position
• Curved profile for factory-style routing

Product Details

Dayco 70399 is a lower radiator hose for applications that require a curved hose with dual inside diameters. The EPDM rubber construction is suited for coolant transfer in demanding engine-bay temperatures, while the SAE J20R4 Class D-1 and SAE J1684 Type EC specifications provide a clear reference for hose construction and performance requirements. This hose is listed for Jeep Cherokee lower radiator hose applications, Jeep Wrangler lower radiator hose applications, and Jeep Comanche lower radiator hose applications, along with select Jeep Wagoneer and 1970-1972 Chevrolet Camaro lower hose applications.

This part cross-references Duralast C70399 for the same application.

What This Hose Helps Address

• Coolant leakage from a cracked or aged lower radiator hose
• Softening, swelling, or collapse in an original hose
• Improper hose fitment caused by incorrect end diameters
• Cooling-system service on Jeep Cherokee, Jeep Wrangler, and Jeep Comanche lower hose routes
• Replacement of a worn curved radiator hose on select Chevrolet Camaro applications

Installation Notes and Tips

Verify the lower hose routing and end diameters before installation. Confirm whether the vehicle is equipped with air conditioning where noted in the fitment data, especially on Jeep Cherokee, Jeep Comanche, and Jeep Wagoneer applications. Inspect hose necks, clamps, and adjacent cooling components for wear before installing the new hose. Ensure the hose is seated fully and routed without twist or contact with hot or moving parts.

Quality Assurance

Dayco manufactures this hose to SAE J20R4 Class D-1 and SAE J1684 Type EC requirements for radiator coolant hose applications. The EPDM construction and application-specific curved shape support consistent fitment on listed Jeep and Chevrolet vehicles.

• Fits 1997-2000 Jeep Cherokee, lower
• Fits 1994-1995 Jeep Cherokee, lower
• Fits 1989-1991 Jeep Cherokee, lower
• Fits 1996 Jeep Cherokee, lower, compatible with vehicles containing air conditioning
• Fits 1992-1993 Jeep Cherokee, lower, compatible with vehicles containing air conditioning
• Fits 1984-1986 Jeep Cherokee, lower, compatible with vehicles containing air conditioning
• Fits 1996 Jeep Cherokee, lower, fits vehicles without air conditioning
• Fits 1992-1993 Jeep Cherokee, lower, fits vehicles without air conditioning
• Fits 1984-1988 Jeep Cherokee, lower, fits vehicles without air conditioning
• Fits 1989-1995 Jeep Wrangler, lower
• Fits 1992 Jeep Comanche, lower, compatible with vehicles containing air conditioning
• Fits 1986 Jeep Comanche, lower, compatible with vehicles containing air conditioning
• Fits 1992 Jeep Comanche, lower, fits vehicles without air conditioning
• Fits 1986-1990 Jeep Comanche, lower, fits vehicles without air conditioning
• Fits 1991 Jeep Comanche, lower
• Fits 1987-1990 Jeep Comanche, lower, w/A.C., 24mm Comp. Head
• Fits 1987-1990 Jeep Comanche, lower, w/A.C., 45mm Comp. Head
• Fits 1987-1988 Jeep Cherokee, lower, w/A.C., 24mm Comp. Head
• Fits 1987-1988 Jeep Cherokee, lower, w/A.C., 45mm Comp. Head
• Fits 1987 Jeep Wagoneer, lower, 24mm Comp. Head
• Fits 1987 Jeep Wagoneer, lower, 45mm Comp. Head
• Fits 1984-1987 Jeep Wagoneer, lower, fits vehicles without air conditioning
• Fits 1984-1986 Jeep Wagoneer, lower, compatible with vehicles containing air conditioning
• Fits 1970-1972 Chevrolet Camaro, lower, fits vehicles without air conditioning