Peterbilt 357/378 Radiators

Frequently Asked Questions About Peterbilt 357/378 Radiators

Will this radiator fit my Peterbilt 357 or 378 without modification?

Radiators for these models are built to match the factory mounting points, tank configuration, and core dimensions of the specific chassis and engine setup they are designed for. Because Peterbilt used different engine options and cooling system configurations across model years, its important to confirm your trucks engine type, year, and OEM part number before ordering to ensure a direct fit.

What is the difference between an aluminum and a copper/brass radiator?

Aluminum radiators are lighter and generally more resistant to corrosion, while copper/brass radiators are often praised for durability and ease of repair if a leak develops. Both styles are commonly available for the 357 and 378, and the right choice usually comes down to your budget, weight considerations, and personal preference or fleet standard.

How do I know if my radiator needs to be replaced versus repaired?

Common signs that point to replacement rather than repair include a cracked or split core, damaged fins that restrict airflow, persistent overheating even after a flush, or leaks at multiple points along the tanks. A qualified technician can pressure test the radiator to help determine whether a repair will hold up or if a full replacement is the more reliable option.

Can I install a replacement radiator myself, or should I have a professional do it?

While some experienced DIY mechanics do replace radiators themselves, the job typically involves draining coolant, disconnecting hoses and brackets, and sometimes removing the fan shroud or grille for clearance. Given the weight of the unit and the importance of a proper seal to prevent leaks, many customers choose to have installation done by a professional shop to ensure everything is set up correctly.

Does this radiator come with mounting brackets, hoses, or a cap included?

This varies by product listing, so its important to check the specific item description before purchasing. Some radiators are sold as a complete unit with brackets and hardware included, while others are core-only and may require you to transfer over your existing brackets, hoses, or cap from your old radiator.