Dayco 87964 HVAC Heater Hose - Pipe To Thermostat

Dayco 87964 Small I.D. Heater Hose

Dayco 87964 is a Small I.D. Heater Hose built for Subaru cooling system service where a 5/8 in. heater hose connection is required. This EPDM hose is a direct-fit HVAC heater hose option for select Subaru Legacy, Outback, Forester, and Impreza applications, including pipe-to-thermostat routing.

Key Features

• EPDM construction for heater hose service
• Black finish for a clean OE-style appearance
• 5/8 in. inside diameter at both ends
• Single I.D. hose design
• Built to SAE J20R3 Class D-1 and SAE J1684 Type EC specifications
• Dayco Small I.D. Heater Hose line for Subaru cooling system replacement

Product Details

This Dayco Small I.D. Heater Hose line focuses on OE-style replacement for Subaru heater circuit routing where compact hose sizing is required. Part number 87964 uses EPDM material and a single I.D. hose design with 5/8 in. inside diameter at each end and 31/32 in. outside diameter at each end. It is listed for Subaru Legacy, Subaru Outback, Subaru Forester, and Subaru Impreza applications, including pipe-to-thermostat positions on select model years. This part number, 87964, is a practical choice when replacing a worn heater hose in the Subaru Legacy or Subaru Outback cooling system.

This part cross-references no listed interchange numbers in the provided data.

Common Uses

• Replacing a cracked or hardened heater hose
• Restoring coolant flow between the pipe and thermostat
• Addressing coolant seepage at a 5/8 in. hose connection
• Repairing Subaru heater hose routing on Legacy, Outback, Forester, or Impreza models
• Servicing an aging HVAC heater hose in the engine bay

Installation Notes

Verify hose routing, end diameters, and position before installation. Confirm the application matches the listed Subaru Legacy, Outback, Forester, or Impreza fitment for your year and engine layout. Inspect adjoining pipes, clamps, and thermostat connections for wear before installing Dayco 87964. Because this hose is specified as a small I.D. heater hose, match the 5/8 in. ends to the vehicle’s existing connection points.

Quality Assurance

Dayco lists this hose to SAE J20R3 Class D-1 and SAE J1684 Type EC standards, supporting consistent heater hose construction for automotive cooling system service.