CSF 3970 Radiator

OE-Style Radiator for Toyota Highlander and Grand Highlander

CSF 3970 is a cross flow radiator built with an aluminum core and plastic tanks in an OE-style layout. It is engineered for direct replacement use on select Toyota Highlander and Toyota Grand Highlander applications, with upgraded B-tube construction for improved heat transfer and durability.

Key Features

• Aluminum core with plastic tank construction
• Cross flow design with 1-row core
• Core thickness: 5/8 in.
• Inlet: 1 1/2 in. left; outlet: 1 1/2 in. right
• Core dimensions: 27 9/16 in. length x 22 5/16 in. width
• OE-style replacement with stronger B-tube design
• CSF part number 3970
• Cross-references Bosch 13842 for the same application

Detailed Description

CSF 3970 is designed for cooling-system service on 2020-2025 Toyota Highlander and 2024-2026 Toyota Grand Highlander models. The radiator uses an aluminum core paired with plastic tanks, matching the OE-style layout while incorporating a higher-performance B-tube design for improved cooling efficiency. With a 5/8-inch core thickness, cross flow configuration, and 1 1/2-inch inlet and outlet sizing, this radiator is built around the factory-style fitment requirements of these Toyota SUVs. If you are replacing a worn or leaking radiator on a Toyota Highlander or Toyota Grand Highlander, CSF 3970 provides a direct-fit cooling solution backed by CSF’s long-running radiator manufacturing experience.

What This Radiator Helps Address

• Coolant leaks from a damaged or aging radiator tank or core
• Overheating caused by restricted or inefficient heat exchange
• Cooling-system service needs after radiator corrosion or wear
• Replacement of a factory-style radiator on Toyota Highlander and Grand Highlander models
• Restoration of stable engine operating temperatures

Installation Notes and Tips

Verify inlet and outlet orientation before installation: this unit uses a left-side inlet and right-side outlet. Confirm radiator dimensions and mounting layout against the original part before removal. Transfer any vehicle-specific components required by the application, and inspect hoses, clamps, and coolant condition during replacement. This part is listed for 2020-2025 Toyota Highlander and 2024-2026 Toyota Grand Highlander applications.

Quality Assurance

CSF manufactures radiators to high-performance standards and validates cooling performance through laboratory wind tunnel testing. The brand states its factories are ISO/TSO certified and that it has supplied radiators worldwide for more than 50 years.