Dayco 86504 Engine Coolant Bypass Hose - Throttle Body To Engine

Dayco 86504 Small I.D. Heater Hose

Dayco 86504 is a Small I.D. Heater Hose built for engine coolant bypass service where a compact 1/4 in. inside diameter is required. Made from EPDM and finished in black, this single I.D. hose is specified for throttle body to engine routing on a wide range of GM trucks, SUVs, and vans.

The Dayco Small I.D. Heater Hose line focuses on replacement hoses for tight coolant connections and bypass circuits. Part number 86504 follows SAE J20R3 Class D-1 and SAE J1684 Type EC specifications for applications that call for a durable coolant hose with the correct small-diameter fit.

• EPDM construction for coolant hose service
• 1/4 in. inside diameter at both ends
• Single I.D. hose design for throttle body to engine routing
• Black finish
• SAE J20R3 Class D-1 and SAE J1684 Type EC specification
• Cross-references ACDelco 14754S for the same application

Detailed Product Information

This engine coolant bypass hose is designed for vehicles that use a small-diameter heater hose connection between the throttle body and engine. The EPDM rubber construction supports coolant transfer in a compact routing path, while the 17/32 in. outside diameter at each end helps match the intended connection size. Dayco 86504 is a direct-fit style replacement for many Chevrolet Silverado, GMC Sierra, and GMC Yukon applications, along with related Cadillac, Hummer, and Saab models.

Compatible With 2000-2006 Chevrolet Tahoe, Throttle Body To Engine; 1999-2006 Chevrolet Silverado 1500, Throttle Body To Engine; and 2000-2006 GMC Yukon, Throttle Body To Engine. It also appears in fitment for Chevrolet Trailblazer, GMC Envoy, and GMC Sierra 1500 applications, making Dayco 86504 a relevant search match for owners looking for a small I.D. heater hose for GM coolant bypass routing.

Common Problems This Hose Can Address

• Cracked or hardened small-diameter coolant hose
• Coolant seepage at the throttle body to engine hose route
• Incorrect hose size during heater hose replacement
• Degraded EPDM hose material from age and heat cycling
• Loss of proper coolant bypass flow through the small I.D. line

Installation Notes and Tips

Verify the hose path, end diameters, and position before installation. This part is listed for throttle body to engine use and also appears in some N/A-position fitments, so confirm the vehicle-specific routing against the original hose. No heat shield or protective sleeve is included. Check clamp condition and inspect adjoining coolant fittings for wear before installing the new hose.

Quality Assurance

Dayco 86504 is built to SAE J20R3 Class D-1 and SAE J1684 Type EC requirements for the listed coolant hose applications. The part number 86504 is also referenced by Gates 18623, CARQUEST 18623, Duralast B86504, NAPA 10623, and General Motors 12570528 for the same application.