CSF 3697 Radiator

OE-Style Cooling for Toyota Applications

CSF radiator Part Number 3697 is an OE-style replacement built with a plastic tank and aluminum core design for dependable engine cooling. It is engineered for the Toyota 4Runner and Toyota FJ Cruiser applications listed below, with fitment coverage across 2003-2014 model years.

The CSF 1 Row Plastic Tank Aluminum Core line focuses on factory-style construction with performance validation. CSF states its radiators are manufactured to high performance standards, wind tunnel tested for cooling validation, and produced in ISO/TSO certified facilities.

Key Features

• 1-row cross-flow radiator design
• Plastic tank and aluminum core construction
• Core thickness: 7/8 in.
• Core width: 23 1/4 in.; core length: 25 9/16 in.
• Inlet diameter: 1 5/16 in., right side
• Outlet diameter: 1 5/16 in., left side
• High-efficiency plate-type oil cooler section: 9 13/16 in.
• OE-style plastic tanks with aluminum core
• Cap not included; CSF cap number 4514

Detailed Description

CSF 3697 is a direct-fit radiator for 2003-2010 Toyota 4Runner and 2007-2014 Toyota FJ Cruiser applications. The cross-flow layout, single-row core, and OE-style tank construction are designed to match factory cooling system architecture while maintaining the dimensions and hose locations needed for proper installation. This part cross-references DENSO Auto Parts 221-3155 and Spectra Premium CU13144 for the same application.

As part of CSF’s 1 Row Plastic Tank Aluminum Core product line, this radiator reflects the brand’s long-running focus on factory-style cooling components for a wide range of vehicles. The design is built around aluminum heat transfer efficiency with durable plastic end tanks, making it a practical replacement when the original radiator shows age, leakage, or reduced cooling performance. Part Number 3697 is also listed with multiple interchange references, including APDI 8012580 and Bosch 13144.

Common Cooling Issues This Radiator Addresses

• Coolant leaks from cracked or aged radiator tanks
• Overheating caused by restricted or inefficient heat transfer
• Loss of cooling performance from a worn factory radiator
• Damaged inlet or outlet connections
• Replacement needs after corrosion or internal clogging

Installation Notes and Fitment

• Fits 2007-2014 Toyota FJ Cruiser, N/A; OE style design; use Micro, 16 psi cap; 1 row plastic tank aluminum core
• Fits 2003-2010 Toyota 4Runner, N/A; OE style design; use Micro, 16 psi cap; 1 row plastic tank aluminum core
• Verify hose routing, inlet and outlet orientation, and core dimensions before installation
• Use the specified Micro 16 psi cap application note where required
• Confirm the vehicle’s cooling system is clean and free of debris before installing the new radiator

Quality Assurance

CSF manufactures radiators in ISO/TSO certified facilities and validates cooling performance through laboratory testing. The brand reports more than 30 million radiators sold worldwide over 50 years of production, supporting a broad OE-style replacement catalog for Toyota 4Runner and Toyota FJ Cruiser cooling system service.