All Aluminum Filler Neck

Replace one of the cooling system's weakest components with the Koyorad Aluminum Filler Neck for the 2022+ Toyota GR86 and Subaru BRZ. Designed as a direct replacement for the factory plastic filler neck, this upgrade provides improved durability, enhanced reliability, and additional functionality for enthusiasts who demand more from their cooling system.

Precision-crafted from billet aluminum, the Koyorad Filler Neck eliminates the cracking, warping, and steam erosion commonly associated with the factory plastic unit after repeated heat cycles. It's the perfect complement to any upgraded cooling system and is highly recommended for vehicles that see spirited street driving, track days, drifting, or forced induction applications.

An integrated 1/8" PT sensor port allows for the easy installation of an aftermarket coolant temperature sensor without requiring additional adapters or modifications. The filler neck also converts the factory cap design to a more robust deep-plunger radiator cap, providing improved sealing and cooling system reliability.

Please Note: This filler neck requires the use of a Koyorad SK-C13 deep-plunger radiator cap (or another compatible deep-plunger style cap). The factory radiator cap is not compatible with this filler neck due to its different sealing design.

For the ultimate OEM+ cooling package, pair this filler neck with either the Koyorad Hyper V-Series Radiator or the Koyorad Hyper Core Competition Radiator. Together, they replace the factory plastic cooling components with premium all-aluminum construction for maximum reliability and performance.

Features:

• Fits 2022+ Toyota GR86 (ZN8)
• Fits 2022+ Subaru BRZ (ZD8)
• CNC-machined billet aluminum construction
• Replaces the factory plastic filler neck
• Eliminates cracking and steam erosion common with OEM plastic units
• Integrated 1/8" PT sensor port for aftermarket coolant temperature sensors
• Requires Koyorad SK-C13 deep-plunger radiator cap (sold separately)
• Factory radiator cap is not compatible
• Direct bolt-on replacement
• Ideal companion to the Koyorad Hyper V-Series and Competition Spec radiators
• Improves cooling system durability and long-term reliability