Toyota Radiator Cap Sub-Assy 16401-31480 OEM replacement, direct-fit, factory pressure-rated

Toyota Genuine Parts Cap Sub-Assy, Radiat (16401-31480) is the original equipment radiator cap assembly engineered by Toyota to replace the factory part for reliable cooling system performance.

This OEM radiator cap sub-assembly (part number 16401-31480) is a Toyota-manufactured replacement designed for direct fit and function in compatible Toyota models. Unlike aftermarket alternatives, this cap is produced to the specifications Toyota set for sealing pressure, materials, and dimensional tolerances so it integrates with your vehicle's cooling system without modification. It’s intended for technicians, vehicle owners, and fleet managers who prefer factory-authorized components to maintain vehicle integrity and resale value.

How does this radiator cap differ from aftermarket options?

The Toyota Genuine cap adheres to original engineering tolerances and is made from materials specified for Toyota cooling systems. Aftermarket caps can vary in pressure rating and fit, which may affect cooling performance or lead to premature wear. Choosing the OEM cap reduces the risk of compatibility issues and helps preserve factory warranties where applicable.

• Exact OEM pressure rating and valve specifications
• Factory-approved materials for sealing and durability
• Direct fit—no adapters or modifications required
• Manufactured and quality-checked by Toyota

When should I replace the radiator cap sub-assy 16401-31480?

Replace the radiator cap if you notice coolant loss, engine overheating, or visible damage to the cap, seal, or pressure valve. Regular inspection during routine maintenance is advised, especially for older vehicles or those exposed to heavy use. If the cap’s pressure valve fails, it can allow coolant to boil or leak, affecting system performance.

• Visible cracks, deformities, or a brittle seal
• Persistent coolant loss or low coolant level warnings
• Overheating episodes linked to pressure loss
• Recommended replacement during thermostat or radiator service

Will this cap install easily during DIY maintenance?

Yes — the Toyota cap sub-assy 16401-31480 is designed for tool-free replacement in most applications where the radiator filler neck matches the original equipment. Always allow the engine to cool before removing the cap to avoid scalding from hot coolant or steam. Follow vehicle-specific service instructions for safe removal and installation.

• Direct-replacement design for OEM-compatible filler necks
• No special tools required for most installations
• Safe replacement only when engine is cool
• Follow Toyota service manual torque/engagement guidance

What vehicle coverage and part assurance does Toyota provide?

This part is vehicle-specific and intended to match the original factory component. Verify part number 16401-31480 against your vehicle’s year, model, and engine configuration to ensure compatibility. Purchase through authorized channels to confirm authenticity and Toyota quality assurance.

• OEM part number: 16401-31480 for exact cross-reference
• Vehicle-specific fit—check VIN or parts catalog for match
• Sold as genuine Toyota part, not an aftermarket substitute
• Backed by Toyota manufacturing standards and inspections

Who is this for: Owners and technicians who prioritize factory-fit components, fleet operators maintaining Toyota vehicles to original specifications, and anyone completing a cooling-system repair that requires the precise pressure and sealing characteristics of the original radiator cap. If you value compatibility, documented fitment, and parts manufactured under Toyota quality controls, this genuine cap sub-assy is the appropriate replacement component.