Dayco 87690 HVAC Heater Hose

Dayco Small I.D. Heater Hose 87690

Dayco 87690 is a Small I.D. Heater Hose built for heater circuit service in select Toyota, Geo, Chevrolet, and Pontiac applications. It uses EPDM construction and a 5/8 in. inside diameter at both ends for a direct replacement in heater hose routing where the original hose size matches.

Key Features

• EPDM rubber construction for heater hose service
• Black finish for a factory-style appearance
• 5/8 in. inside diameter at both ends
• Single I.D. hose design
• Meets SAE J20R3 Class D-1 and SAE J1684 Type EC specifications
• Dayco Small I.D. Heater Hose line for select HVAC hose applications

Product Details

This Dayco heater hose is part of the Small I.D. Heater Hose product line, built for HVAC hose routing where a 5/8 inch hose is required. The EPDM material is commonly used in coolant and heater hose applications because it handles heat and coolant exposure in engine bay service. Dayco 87690 is a direct-fit style replacement for vehicles including 1993-1997 Geo Prizm, 1993-1997 Toyota Corolla, 1994 Toyota Corolla, 1985-1988 Chevrolet Nova, 1984-1988 Toyota Corolla, and 1984-1986 Pontiac Fiero in the listed heater and valve-to-engine positions. This part cross-references ACDelco 16078M and Gates 18853 for the same application.

Common Uses

• Replacing a cracked or hardened heater hose
• Restoring coolant flow between the heater circuit and engine
• Addressing coolant seepage at a worn hose section
• Correcting a hose that no longer seals properly on 5/8 in. fittings
• Servicing heater inlet, heater-to-engine, heater-to-valve, valve-to-engine, or heater-to-pipe routing

Installation Notes

Verify the hose routing, end diameters, and position before installation. Match the original 5/8 in. inside diameter and confirm the application against the vehicle’s heater hose path, especially on Toyota Corolla, Geo Prizm, and Pontiac Fiero configurations. Inspect adjoining clamps, pipes, and fittings for corrosion or damage before installing the new hose.

Quality Assurance

Dayco manufactures this heater hose to SAE J20R3 Class D-1 and SAE J1684 Type EC specifications for HVAC hose service. The EPDM construction and application-specific sizing support consistent replacement performance in the listed vehicles.