Dayco 87879 HVAC Heater Hose - Heater To Engine or Heater To Tee

Dayco Small I.D. Heater Hose for HVAC Service

Dayco Part Number 87879 is a dual I.D. heater hose built for HVAC heater hose routing where different inside diameters are required at each end. Made from EPDM and finished in black, it is specified for heater-to-engine and heater-to-tee applications on select Acura, Buick, and Chevrolet vehicles.

Use this Dayco Small I.D. Heater Hose when you need a replacement that matches the original hose layout and SAE requirements for the application. Part number 87879 is listed for 2007-2012 Acura RDX heater to engine service, plus 1994-1996 Buick Roadmaster and 1994-1996 Chevrolet Caprice heater to tee routing.

Key Features

• EPDM construction for HVAC 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
• No heat shield and no protective sleeve
• Dayco 87879 heater hose for select Acura RDX, Buick Roadmaster, and Chevrolet Caprice applications

Product Details

Dayco’s Small I.D. Heater Hose line focuses on replacement heater hose routing where compact sizing and correct end diameters matter. This hose uses EPDM rubber for HVAC service and a dual inside diameter layout to match the vehicle’s heater circuit connection points. The listed dimensions are 5/8 in. inside diameter at end 1 and 3/4 in. inside diameter at end 2, with outside diameters of 21/32 in. and 25/32 in. respectively. Part number 87879 is a direct-fit style replacement for the specified heater hose positions on the vehicles shown below.

This part cross-references Gates 19078 and NAPA 11078 for the same application.

What It Helps Fix

• Cracked or hardened heater hose rubber
• Coolant leaks at heater hose connections
• Restricted heater coolant flow from deteriorated hose material
• Incorrect hose sizing at dual-diameter heater connections
• Service replacement needs for heater-to-engine and heater-to-tee routing

Installation Notes

• Verify end diameters before installation: 5/8 in. and 3/4 in.
• Confirm the vehicle uses heater-to-engine or heater-to-tee routing listed for this part
• Inspect clamps, fittings, and adjoining coolant lines before reassembly
• Drain coolant as needed and refill/bleed the system according to the vehicle service procedure
• Check for leaks after the engine reaches operating temperature

Quality Assurance

Part number 87879 is manufactured to SAE J20R3 Class D-1 and SAE J1684 Type EC specifications for heater hose service. It is an EPDM heater hose from Dayco’s Small I.D. Heater Hose line, engineered for the listed HVAC applications.

• Fits 2007-2012 Acura RDX, Heater To Engine
• Fits 1994-1996 Buick Roadmaster, Heater To Tee
• Fits 1994-1996 Chevrolet Caprice, Heater To Tee