Fel-Pro 35703 Engine Coolant Thermostat O-Ring

Fel-Pro 35703 Engine Coolant Thermostat O-Ring

Fel-Pro 35703 is a premium engine coolant thermostat O-ring built for sealing performance in cooling system service. It uses application-specific materials to help deliver the vehicle sealing professionals expect on Ram 2500 and Ram 3500 applications.

Key Features

• Premium-grade thermostat O-ring for cooling system sealing
• Application-specific material selection for a precise seal
• Engine coolant thermostat O-ring replacement for service work
• Compatible with 2003-2010 Dodge Ram 2500 and 3500
• Compatible with 2011-2024 Ram 2500 and 3500
• Fel-Pro part number 35703 for easy identification

Detailed Description

Fel-Pro 35703 is an engine coolant thermostat O-ring designed for sealing the thermostat housing area in cooling system repairs. Fel-Pro focuses on vehicle-specific sealing solutions, and this premium O-ring reflects that approach with materials selected for the application rather than a one-size-fits-all design. It is a direct-fit sealing component for Ram 2500 and Ram 3500 trucks across the listed model years, including 2003-2010 Dodge Ram 2500 and Ram 3500, plus 2011-2024 Ram 2500 and Ram 3500. This part number, 35703, is a practical choice when replacing a thermostat seal during cooling system maintenance.

This part cross-references MAHLE C31858 for the same application.

What It Helps Address

• Coolant seepage at the thermostat housing seal
• Loss of sealing integrity during thermostat service
• Cooling system leaks traced to a worn O-ring
• Maintenance on Ram 2500 and Ram 3500 thermostat assemblies
• Replacement of a hardened or flattened coolant seal

Installation Notes and Tips

Inspect the thermostat housing and sealing surfaces before installation. Clean away old coolant residue, corrosion, and debris so the new O-ring can seat evenly. Verify the part number 35703 against the vehicle year and model before assembly, especially on Dodge Ram 2500 and Ram 3500 trucks from 2003-2010 and Ram 2500 and Ram 3500 trucks from 2011-2024.

Quality Assurance

Fel-Pro gaskets and sealing components are built around application-specific materials and vehicle-focused sealing requirements. That engineering approach supports consistent sealing performance in cooling system service.