Y6740003 Genuine Paccar HVAC Heater Core

Product Overview

The Y6740003 is a genuine Paccar HVAC heater core specified for Peterbilt and Kenworth T680 and T880 truck cabin heating applications, with a 2024 Kenworth T880 identified in the supplied take-off information. This heat exchanger transfers thermal energy from circulating engine coolant to air passing through the HVAC housing, allowing the vehicle's heating system to deliver warmed air into the passenger compartment.

Product Features

The Y6740003 Paccar HVAC heater core is a coolant-to-air heat exchanger that supplies thermal energy to the truck's cabin heating system through the existing HVAC airflow arrangement.

• Transfers heat from circulating engine coolant into the cabin ventilation airstream
• Allows warmed air to pass through the vehicle's designated HVAC distribution system
• Operates within the coolant circuit connected to the truck heater assembly
• Provides an internal heat exchange surface for the passenger compartment heating process
• Works with the existing blower airflow to deliver heat through cabin outlets
• Fits the specified heater core application within compatible Paccar cab configurations

General Specifications

Installation Notes

The Y6740003 should be installed after draining the necessary coolant from the heating circuit, inspecting the heater hose connections, and checking the HVAC housing for accumulated debris, coolant residue, or damaged sealing surfaces. Once the heater core is secured and the coolant lines are connected, refill and bleed the cooling system according to the applicable service procedure, inspect for leaks, and verify that heated air reaches the cab ventilation outlets.

Always verify the original heater core part number, truck cab configuration, HVAC housing dimensions, coolant connection arrangement, and heating system layout before installation.