JTL Parts Coolant Reservoir Tank 603-5403 (Engine Coolant Expansion Tank / Radiator Overflow Reservoir) – Replacement for N5346001 / T1673008 / ST6000 – Heavy Duty Application

COOLANT RESERVOIR 603-5403 Engine Coolant Tank

Replacement for 603-5403 / N5346001 – Heavy Duty Application

The Coolant Reservoir 603-5403 is designed for heavy-duty trucks, providing a reliable storage and pressure control system for engine coolant. This reservoir helps maintain proper coolant levels, prevents overheating, and ensures stable engine temperature under demanding operating conditions.

Product Details

• Part Number: 603-5403
• Type: Engine Coolant Reservoir (Expansion Tank)
• Application: Cooling System
• Cross Reference: 603-5403, N5346001, T1673008, ST6000, 5751023

Key Benefits

• Maintains proper coolant level in the system
• Helps prevent engine overheating
• Built for high-pressure cooling systems
• Durable construction for heavy-duty applications
• Ensures stable engine temperature control

Function

• Stores excess coolant during thermal expansion
• Returns coolant to the system as needed
• Maintains pressure balance in the cooling system
• Supports consistent engine cooling performance

High-Quality Construction

• High-strength reinforced plastic body
• Heat and vibration resistant design
• Includes pressure-rated cap (15 PSI)
• OEM-style fit and durability

Vehicle Fitment

Compatible with heavy-duty trucks such as:

• Kenworth Trucks
• Peterbilt Trucks

Fits Models

• Kenworth T600 / T800 / W900
• Peterbilt 365 / 367 / 386 / 389

Note: Fitment may vary depending on engine and configuration. Always verify part number before purchase.

Replaces / Cross Reference Numbers

• 603-5403
• N5346001
• T1673008
• 5751023
• ST6000 / ST6001 / ST6002

Installation

• Direct replacement design
• Includes mounting points for easy installation
• No modifications required

Package Includes

• 1 x Coolant Reservoir
• 1 x Pressure Cap