Dayco 87730 HVAC Heater Hose

Dayco Small I.D. Heater Hose 87730

Dayco 87730 is a small inside diameter heater hose built for heater circuit routing in select Ford, Mercury, Mazda, and Chevrolet applications. It uses EPDM construction and a black finish, with 5/8 in. inside diameter at both ends for direct replacement of the specified heater hose path.

Key Features

• EPDM rubber construction for heater hose service
• 5/8 in. inside diameter at both ends
• Single I.D. hose design for small-diameter heater routing
• Black finish for a clean OE-style appearance
• Meets SAE J20R3 Class D-1 and SAE J1684 Type EC specifications
• Dayco Small I.D. Heater Hose line for vehicle-specific heater connections

Product Details

The Dayco Small I.D. Heater Hose line is built for heater hose applications that require a consistent 5/8 in. inside diameter and reliable coolant transfer through the HVAC system. Part number 87730 is specified for heater-to-pipe, pipe-to-heater, tee-to-pipe, heater inlet, cylinder head-to-heater, engine-to-heater, and heater-to-pipe-1 routing positions across the listed vehicles. This part cross-references Gates 18937 for the same application.

Compatible With 2002-2009 Ford Explorer, heater to pipe; 2004-2005 Ford Explorer, heater inlet; 2002-2009 Mercury Mountaineer, heater to pipe; 2001-2005 Mazda Miata, cylinder head to heater; and 2005-2006 Chevrolet Uplander, tee to pipe. Dayco 87730 also appears in additional Ford Explorer, Explorer Sport Trac, Explorer Sport, Mountaineer, and Mazda Miata heater hose applications listed in the fitment data.

Common Problems This Hose Addresses

• Cracked or hardened heater hose material
• Coolant seepage at a small-diameter heater hose connection
• Restricted heater coolant flow from a deteriorated hose
• Incorrect hose size for a 5/8 in. heater circuit connection
• Replacement needs for heater inlet, heater outlet, or pipe routing service

Installation Notes and Tips

Verify the hose path, end diameters, and routing position before installation. Confirm the application against the vehicle’s heater circuit layout, especially on Ford Explorer, Mercury Mountaineer, and Mazda Miata models where multiple heater hose routes are listed. Inspect adjoining pipes, tees, and clamps for wear or corrosion before installing Dayco 87730.

Quality Assurance

Dayco 87730 is manufactured to SAE J20R3 Class D-1 and SAE J1684 Type EC standards for heater hose service. The EPDM construction and OE-style sizing support consistent fitment in the specified heater hose applications.