Dayco 87858 HVAC Heater Hose - Heater To Pipe

Dayco Small I.D. Heater Hose 87858

Dayco 87858 is a dual I.D. heater hose for HVAC heater hose routing where a 5/8 in. end connects to a 3/4 in. end. Built from EPDM and finished in black, it is made for heater-to-pipe service in select Pontiac, Oldsmobile, and Chevrolet applications.

This Small I.D. Heater Hose line focuses on compact heater hose connections that require different inside diameters at each end. For service work on the Pontiac Grand Am, Oldsmobile Alero, Chevrolet Malibu, and Oldsmobile Cutlass, Dayco 87858 provides the correct dual-size hose configuration for the heater circuit.

Key Features

• Brand: Dayco
• Part number: 87858
• Dual I.D. hose with 5/8 in. end 1 and 3/4 in. end 2
• EPDM construction for HVAC heater hose service
• Black finish
• Meets SAE J20R3 Class D-1 and SAE J1684 Type EC specifications
• Heater to pipe position
• Fits select 1997-2005 Pontiac Grand Am, Oldsmobile Alero, Chevrolet Malibu, and Oldsmobile Cutlass applications

Detailed Description

Dayco 87858 is an HVAC heater hose built for vehicles that use a small I.D. dual-size connection in the heater circuit. The EPDM hose material is suited for coolant transfer in heater hose service, while the dual I.D. design helps match the different connection sizes found at the heater-to-pipe location. This part number is a direct service option for select Pontiac Grand Am, Oldsmobile Alero, Chevrolet Malibu, and Oldsmobile Cutlass models.

Dayco 87858 cross-references Gates 19048 for the same application. It is also listed against ACDelco 16135M, CARQUEST 19048, Duralast C87858, Goodyear 63993, and NAPA 11048.

Vehicle Fitment

• Fits 1999-2005 Pontiac Grand Am, Heater To Pipe; HVAC Heater Hose - Thermo End; Small I.D. Heater Hose
• Fits 1999-2004 Oldsmobile Alero, Heater To Pipe; HVAC Heater Hose - Thermo End; Small I.D. Heater Hose
• Fits 1997-2003 Chevrolet Malibu, Heater To Pipe; HVAC Heater Hose - Thermo End; Small I.D. Heater Hose
• Fits 1997-1999 Oldsmobile Cutlass, Heater To Pipe; HVAC Heater Hose - Thermo End; Small I.D. Heater Hose

Common Repair Uses

• Replacing a cracked or leaking heater hose at the heater-to-pipe connection
• Restoring coolant flow through the HVAC heater circuit
• Correcting a hose fitment issue caused by mismatched inside diameters
• Servicing a worn hose on a Pontiac Grand Am, Oldsmobile Alero, Chevrolet Malibu, or Oldsmobile Cutlass
• Addressing coolant seepage, soft hose sections, or age-related hose deterioration

Installation Notes and Tips

Verify the hose routing and both inside diameters before installation. Match the heater-to-pipe position exactly, and inspect adjoining pipes, clamps, and coolant passages for wear or corrosion before reassembly. Confirm that the hose follows the original routing without kinks or tension.

Quality Assurance

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