Dorman 603-5120 Engine Coolant Reservoir - Front

Engine Coolant Reservoir for International Vehicles

This Dorman engine coolant reservoir is an OE FIX replacement for certain International vehicles with a leaking level indicator in the original tank. Part number 603-5120 uses clear plastic construction to remove that common failure point while retaining the pressurized reservoir design.

• Brand: Dorman
• Part number: 603-5120
• Clear plastic reservoir construction
• Pressurized design with 15 psi cap rating
• 7 L capacity
• Includes reservoir and cap
• Mounting brackets included
• Spring-loaded twist cap included
• No level sensor included

OE FIX Design Details

Unlike the original reservoir on certain International truck applications, this replacement eliminates the level-indicator leak point by using an all-clear plastic tank. The reservoir measures 12 inches long and 17.5 inches high, with an irregular shape, five mounting holes, and a pressurized 7 L capacity. Part number 603-5120 is supplied with a cap rated to 15 psi and is built for direct replacement service where the original coolant reservoir has failed.

This part cross-references International 2587279C92 for the same application.

What It Helps Fix

• Coolant loss from a leaking reservoir level indicator
• Cracked or deteriorated coolant tank housing
• Pressure loss at the reservoir cap interface
• Overflow or low-coolant warning concerns caused by reservoir failure
• Replacement needs on International cooling system service jobs

Installation Notes

Verify the reservoir shape, mounting hole count, and cap style against the original unit before installation. Transfer any reusable mounting brackets as needed, and confirm the cooling system is filled and bled according to the vehicle service procedure after replacement. Because this reservoir is pressurized, use only the included cap or an equivalent cap with the correct 15 psi rating.

Quality Assurance

Dorman OE FIX parts are engineered to address known failure points in original components. This reservoir is built as a direct replacement for the specified International coolant reservoir application and includes the cap required for service.