Gates 18303 HVAC Heater Hose

Gates Molded Heater Hose for Tight Engine Bays

The Gates Molded Heater Hose, part number 18303, is a factory-molded EPDM coolant hose built for compact engine compartments where a straight hose will not route correctly. It serves coolant, water, and air applications, and it is also approved for marine use.

Key Features

• Factory-molded, OEM-style shape for accurate routing
• EPDM construction for coolant and heater service
• Small inside diameter: 10 mm (0.38 in) at both ends
• Centerline length: 173 mm (6.8 in)
• Compatible with radiator and HVAC heater hose routing
• Approved for marine applications
• Gates 18303 molded heater hose for space-restricted installations

Product Details

Gates Molded Heater Hose 18303 is made to follow the original hose path in vehicles with tighter engine packaging. The molded design helps maintain proper hose routing around nearby components, while the EPDM material supports coolant transfer in heater and radiator circuits. This hose is a direct-fit style solution for applications such as Toyota MR2, Toyota Celica, and Mitsubishi Expo, where the factory hose shape matters for clearance and alignment. This part cross-references Dayco 87003 for the same application.

Common Problems It Can Help Solve

• Cracked or leaking heater hose at the original molded bend
• Poor hose routing after a repair or engine service
• Restricted clearance in compact engine compartments
• Coolant seepage from aged EPDM hose material
• Incorrect fitment when a straight hose cannot match the factory path

Installation Notes and Tips

Verify end diameters and routing before installation. This hose measures 10 mm at both ends and 173 mm centerline length, so it should be matched to the original path and connection points. Confirm the vehicle position listed in the fitment data, especially on Toyota MR2, Toyota Celica, and Mitsubishi Expo applications where multiple hose locations are shown. Gates 18303 is a molded heater hose, so proper orientation during installation is important for clearance and flow.

Quality Assurance

Gates manufactures this hose as an OEM-style molded replacement for coolant, water, air, and marine service applications. The EPDM construction and factory-molded profile support consistent fit and routing in the listed applications.

Compatible Vehicles

• Fits 1991-1995 Toyota MR2, Engine To Pipe-6
• Fits 1991-1995 Toyota MR2, Thermostat To Pipe-7
• Fits 1988-1993 Toyota Celica, Pipe To Engine
• Fits 1988-1989 Toyota Celica, Pipe To Pipe
• Fits 1988-1989 Toyota Celica, Pipe To Turbocharger
• Fits 1988-1989 Toyota Celica, Turbocharger To Pipe
• Fits 1992 Mitsubishi Expo, Throttle Body To Pipe
• Fits 1985-1986 Mitsubishi Starion, Pipe-3 To Pipe-4
• Fits 1986-1987 Buick Skylark, Throttle Body To Engine
• Fits 1986 Buick LeSabre, Throttle Body To Engine
• Fits 1986 Oldsmobile Delta 88, Throttle Body To Engine
• Fits 1985-1987 Oldsmobile Calais, Throttle Body To Pipe / Throttle Body To Engine
• Fits 1985-1986 Pontiac Grand Am, Throttle Body To Pipe / Throttle Body To Engine