Mishimoto Aluminum Coolant Expansion Tank for Honda Civic Type R (FK8/FL5) – Black

Part Details:

The factory expansion tank on the Civic Type R is plastic, fine for mass production but genuinely prone to failure after repeated heat cycling in the engine bay’s punishing temperatures. This Mishimoto Aluminum Expansion Tank replaces it entirely with a fully welded, 100 percent aluminum design, removing that failure point for good while dressing up one of the more visible corners of the engine bay with a wrinkle black micro-finish that looks like it belongs there.

Internal baffling keeps coolant covering the overflow port during hard braking, long sweepers, or curb-hopping on track days, since coolant pulling away from that port lets air into the system, which means hotspots and inconsistent temperatures down the line. A sight glass gives quick visual confirmation of fluid level without popping the cap, and the kit includes a Mishimoto 1.3 bar filler cap while still retaining compatibility with the stock cap.

Key Features

• Fits 2017 to 2021 Honda Civic Type R (FK8) and 2023 and newer Civic Type R (FL5)
• 100 percent aluminum, fully welded construction
• Removes the failure-prone factory plastic tank
• Internal baffling keeps coolant at the overflow port under hard driving
• Sight glass for quick fluid level checks
• Includes Mishimoto 1.3 bar (19psi) filler cap, retains stock cap compatibility
• Wrinkle black micro-finish

Recommended Supporting Components

• FK8 vs FL5 Honda Civic Type R: What Actually Changed confirm you have the right chassis before ordering.
• Most Common Honda Civic Type R Failures and How to Prevent Them a failing plastic tank is a preventable issue worth knowing about.