Dayco 87603 HVAC Heater Hose

Dayco Small I.D. Heater Hose 87603

Dayco 87603 is a Small I.D. Heater Hose built for HVAC heater hose service where a dual inside diameter is required. Made from EPDM and finished in black, it provides the correct hose sizing for heater circuit routing on a wide range of vehicles, including Jeep Wrangler, Ford Econoline, and Dodge Durango applications.

Key Features

• EPDM construction for heater hose use
• Dual I.D. hose design with 5/8 in. end 1 and 3/4 in. end 2
• Black finish for a clean OE-style appearance
• Built to SAE J20R3 Class D-1 and SAE J1684 Type EC specifications
• Small I.D. heater hose routing for select HVAC hose and pipe connections
• Dayco part number 87603 for easy identification

Product Details

The Dayco Small I.D. Heater Hose line is intended for heater and coolant transfer paths that require precise inside diameters and reliable routing. Part number 87603 uses EPDM rubber for heat and coolant exposure in HVAC service, with a dual I.D. layout that transitions from 5/8 inch to 3/4 inch. This makes it a direct match for many heater-to-pipe, tee-to-engine, pipe-to-heater, and auxiliary water pump routing points found across Ford, Chrysler, GM, Jeep, Nissan, Saturn, and Volkswagen applications. This part cross-references Gates 18070 and NAPA 10070 for the same application.

Common Uses

• Replacing a cracked or softened heater hose
• Restoring coolant flow between heater pipes, tees, and the engine
• Repairing leaks at small I.D. heater hose connections
• Correcting hose fitment on dual-diameter HVAC hose routing
• Servicing heater circuit connections on Jeep Wrangler, Ford Econoline, and Dodge Durango models

Installation Notes

Verify the hose end diameters and routing location before installation. This hose does not include a heat shield or protective sleeve. Confirm the vehicle’s heater hose path, especially on applications listed as pipe-to-heater, heater-to-valve, tee-to-water-pump, or auxiliary water pump-to-pipe. Fits 2012-2014 Jeep Wrangler, Pipe-2 To Engine; Fits 2004-2009 Dodge Durango, Auxiliary Water Pump To Pipe-1; Fits 2008-2009 Saturn Vue, Tee To Pipe-1; Fits 2007 Chrysler Aspen, Auxiliary Water Pump To Pipe; Fits 2005-2006 Buick Terraza, Tee To Engine; Fits 2005 Chevrolet Uplander, Tee To Engine; Fits 2005 Pontiac Montana, Tee To Engine; Fits 2005 Saturn Relay, Tee To Engine; Fits 1993-1996 Ford E-150 Econoline, Pipe To Heater; Fits 1984-1989 Nissan 300ZX, Heater To Pipe.

Quality Assurance

Dayco manufactures this heater hose to SAE J20R3 Class D-1 and SAE J1684 Type EC specifications for heater hose service. The EPDM construction and application-specific sizing support consistent replacement for select OE-style HVAC hose routing.