RK Autowerks Billet Coolant Reservoir, BMW S63TU4

RK Autowerks Billet Coolant Reservoir – BMW S63TU4

Say goodbye to cracked plastic coolant tanks. The RK Autowerks Billet Coolant Reservoir is precision-machined in-house in Texas, USA, as a direct solution to the failure-prone OEM plastic reservoir found on the S63TU4 platform. Crafted from solid 6061 billet aluminum, this reservoir is built for performance, durability, and long-term reliability in high-temperature, high-pressure environments.

Engineered to retain all factory functionality, the billet tank keeps the OEM pressure relief cap and sensor setup. It connects directly to the original fittings using OEM-style quick-connect ports—making this a true plug-and-play upgrade.

Key Features:

• CNC machined from 6061 billet aluminum
• Retains factory pressure cap
• Reuses factory sensor for level monitoring
• Direct-fit OEM connections
• O-ring sealed for leak-free operation
• Internally baffled to reduce slosh and maintain system pressure

Vehicle Fitment:

• 2018 – 2023 BMW F90 M5
• 2019+ BMW F91 / F92 / F93 M8

Installation Note:
You’ll need to transfer the OEM coolant level sensor from the original reservoir. In some cases, removal may require minor trimming. An O-ring is not included—please measure your original and source a replacement locally if needed.