Dayco 88405 HVAC Heater Hose - Thermostat To Heater

Dayco Small I.D. Heater Hose for HVAC Service

Dayco 88405 is a Small I.D. Heater Hose built for heater circuit service in select Chevrolet, GMC, and Isuzu applications. It uses EPDM construction with a protective sleeve to support heat and abrasion resistance in the thermostat-to-heater routing.

This Dayco heater hose is sized with a 23/32 in. inside diameter at both ends and follows SAE J20R3 Class D-1 and SAE J1684 Type EC specifications. It is a direct-fit HVAC heater hose for 1998-2003 Chevrolet S10, 1998-2003 GMC Sonoma, and 1998-2000 Isuzu Hombre thermostat to heater applications.

Key Features

• EPDM rubber construction for heater hose service
• Black finish for a factory-style appearance
• 23/32 in. inside diameter at both ends
• Single I.D. hose design for thermostat-to-heater routing
• Protective sleeve included; heat shield not included
• Built to SAE J20R3 Class D-1 and SAE J1684 Type EC requirements
• Dayco 88405 heater hose for select compact truck and pickup applications

Detailed Description

Dayco’s Small I.D. Heater Hose line focuses on replacement hoses for heater and coolant transfer paths where correct diameter and routing matter. Part number 88405 is formed from EPDM and includes a protective sleeve to help protect the hose in underhood areas near the thermostat and heater connection points. For buyers searching for a Chevrolet S10 heater hose, GMC Sonoma heater hose, or Isuzu Hombre heater hose, this part number 88405 matches the listed thermostat to heater applications.

This hose cross-references ACDelco 14268S and Gates 19747 for the same application.

Common Problems This Hose Can Address

• Cracked or hardened heater hose material
• Coolant seepage at the thermostat-to-heater line
• Restricted heater flow from a deteriorated hose
• Heat-related wear in the hose routing area
• Incorrect hose diameter during heater hose replacement

Installation Notes and Tips

• Verify the 23/32 in. inside diameter before installation.
• Match the thermostat-to-heater routing shown on the vehicle.
• Inspect adjoining clamps, fittings, and nearby coolant hoses for wear before reassembly.
• Confirm clearance around the protective sleeve so the hose does not rub against adjacent components.
• Drain and refill coolant according to the vehicle service procedure after hose replacement.

Quality Assurance

Dayco 88405 is manufactured to SAE J20R3 Class D-1 and SAE J1684 Type EC specifications, supporting consistent heater hose performance for the listed applications.