Radium Engineering Coolant Expansion Tank Kit for Honda Civic Type R FK8 / FL5

Radium Coolant Expansion Tank Kit, Honda Civic Type R (FK8 / FL5)

Application: Honda Civic Type R (2017+) and Acura Integra Type S (2024+)
Part Type: Billet aluminium coolant expansion tank kit
Part Number: 20-0827

Plastic coolant tanks have a reputation for failing over time under constant, intense heat cycling. The Radium 20-0827 replaces the Civic Type R's factory plastic tank with a two-piece CNC-machined aluminium tank, anodised for longevity, that is robust enough for racing and conducts heat better than plastic.

It fits without permanent modification: a custom bracket mounts to existing threaded holes and Radium adapter fittings connect to the factory coolant lines. Internal volume matches the OEM tank, and the two internal chambers are joined by cross-over passages at the top and bottom, with an internal swirl feature to help de-aerate the cooling system.

Key Features

• Two-Piece Billet Aluminium: CNC machined and anodised
• OEM Volume: Internal volume equivalent to the OEM tank, so no coolant capacity is lost
• Dual Chamber: Cross-over passages at the top and bottom
• Swirl De-Aeration: Internal swirl feature helps remove air from the system
• Bolt-In: Custom bracket uses existing threaded holes; adapter fittings connect to the factory lines
• Race Proven: Used in race and street vehicles worldwide

What's Included

• Two-piece billet aluminium tank
• Aluminium mounting bracket
• Aluminium adapter fittings
• Heater hose, 5/16in
• Overflow hose, 7/32in
• Stainless steel hardware

Important Notes

• The OEM 1.3 bar Honda pressure cap can be re-used
• Radium Type-A pressure caps with various pressure ratings are available separately
• Installation instructions are available in the Instructions tab

Vehicle Fitment

• Honda Civic Type R FK8 (2017–2021)
• Honda Civic Type R FL5 (2023+)
• Acura Integra Type S (2024+)

If you're unsure whether this will fit your vehicle, contact our team of experts via email at hello@iilumolab.com and send through a few photos of the car for us to verify fitment.

Installation

We always recommend professional fitment for guaranteed satisfaction. If you're wanting a hassle-free installation, feel free to contact our friendly team as we offer installation services in-store at our Melbourne workshop. For more details, contact us here.

Note

Upon receiving the item, please ensure that the part is indeed the correct item you have ordered. This can be achieved by checking labels on the packaging. Please also ensure a proper test fit of the item is conducted prior to paint and/or installation. Returns/Warranty claims will be voided if the item has been tampered with, or is no longer in resalable/new condition.