Gates 18798 HVAC Heater Hose

Gates 18798 Molded Heater Hose Overview

Gates 18798 is a molded heater hose built for tight engine bays where a factory-shaped coolant line is needed. This OEM-style hose uses EPDM construction and a small inside diameter to support coolant, water, and air routing in demanding HVAC and cooling system applications.

Compatible With Toyota Prius, Prius Prime, Prius V, Prius Plug-In, Lexus CT200h, and select Ford, Mercury, Mazda, Cadillac, Chevrolet, Isuzu, and Oldsmobile applications, Gates 18798 is shaped for direct routing where straight hose stock will not follow the original path.

Key Features

• Factory-molded, OE-style heater hose for precise routing
• EPDM construction for coolant, water, and air service
• Small I.D. design for compact engine compartments
• End I.D. of 0.62 in. / 16 mm at both ends
• Centerline length of 10.2 in. / 259 mm
• Molded profile for HVAC heater hose and radiator circuit routing
• Approved for marine applications

Product Details

The Gates Molded Heater Hose line focuses on shaped replacement hoses that match original routing requirements in modern and older vehicles. Part number 18798 follows that approach with a molded EPDM body and equal 0.62-inch ends, making it suitable for heater, coolant, and air transfer paths where bend shape and length matter. This part cross-references Dayco 71575 for the same application.

Vehicle coverage includes 2010-2017 Toyota Prius, 2017 Toyota Prius Prime, 2012-2017 Toyota Prius V, 2012-2015 Toyota Prius Plug-In, and 2011-2014 Lexus CT200h, along with additional Ford Explorer, Mercury Mountaineer, Toyota Sienna, and other listed applications. Gates 18798 is also referenced by the part number 18798 in catalog listings for the same molded heater hose application.

Common Problems This Hose Can Address

• Cracked or hardened heater hose material
• Incorrect hose routing in tight engine compartments
• Coolant leaks at a molded hose section
• Restricted heater flow from a damaged or collapsed hose
• Replacement needs for radiator and HVAC coolant hose routing

Installation Notes and Tips

Verify end diameter, centerline length, and molded shape against the original hose before installation. Confirm the vehicle-specific position listed in the fitment data, such as Pipe-5 To Pipe-6, Pipe-3 To Auxiliary Heater, Heater To Valve, Pipe-2 To Thermostat, Pipe To Engine, or Pipe To Radiator. For Toyota Prius and Lexus CT200h applications, match the original routing carefully to preserve clearance around nearby components.

Inspect adjoining pipes, clamps, and sealing surfaces before installing Gates 18798. Flush the cooling system if contamination or hose deterioration is present, and confirm the hose is seated without twist or tension after installation.

Quality Assurance

Gates manufactures molded coolant and heater hoses to OE-style dimensions for direct-fit routing in automotive HVAC and cooling systems. The EPDM construction and factory-molded shape support consistent fitment across the listed vehicle applications.