Gates 23999 HVAC Heater Hose - Heater - Left Side or Heater To Pipe

Gates 23999 Molded Coolant Hose Overview

The Gates 23999 molded coolant hose is built for HVAC heater circuit service on select Ford and Lincoln applications. It uses EPDM, plastic, and steel construction with a molded shape and a female quick connector to match the routing and connection style used in the original system.

Gates Molded Coolant Hose products are application-specific assemblies that follow OE-style layouts and integrated component requirements. This Gates 23999 hose is made for direct replacement use on the heater side of the cooling system, including Ford F-150 and F-350 models and the Lincoln Mark LT.

Key Features

• Application-specific molded coolant hose for HVAC heater service
• EPDM, plastic, and steel construction
• Female quick connector included in the hose assembly design
• Molded profile for factory-style routing
• Centerline length: 23.16 in. (588 mm)
• End 1 inside diameter: 0.63 in. (16 mm)
• End 2 inside diameter: 0.63 in. (16 mm)
• Compatible with Ford F-150 heater to pipe and heater - left side applications
• Compatible with Ford F-350 heater - left side applications
• Compatible with Lincoln Mark LT heater - left side applications

Detailed Description

Gates 23999 is a molded HVAC heater hose engineered for specific vehicle routing and connection points. The assembly uses a female quick connector and molded construction to follow the original hose path, helping maintain proper coolant flow through the heater circuit. This part number is used on 2005-2008 Ford F-150 heater to pipe and heater - left side applications, 2005-2008 Ford F-350 heater - left side applications, and 2006-2008 Lincoln Mark LT heater - left side applications. This part cross-references BBB Industries 16658 for the same application.

Common Replacement Uses

• Cracked or deteriorated heater hose sections
• Leaking quick-connect hose connections
• Restricted coolant flow through the heater circuit
• Damaged molded hose routing that no longer matches factory shape
• Service replacement for a worn Gates 23999 hose assembly

Installation Notes and Tips

Verify the vehicle year, engine-side routing, and heater connection location before installation. Confirm the female quick connector and both 16 mm hose ends match the original connection points. Inspect adjoining pipes, clamps, and seals for wear before transferring the new hose into place. For fitment reference, this hose is listed for 2005-2008 Ford F-150, 2005-2008 Ford F-350, and 2006-2008 Lincoln Mark LT heater-side applications.

Quality Assurance

Gates is a recognized automotive aftermarket supplier with a focus on modular coolant hose assemblies that mirror OE-style component layouts. The 23999 molded coolant hose is built to application-specific dimensions and connection requirements for consistent replacement service.