Coolant expansion tank bottle. Porsche 9J1.1 Taycan 2020-24  ❭  9J1121407A

Coolant expansion tank bottle.
This genuine coolant expansion tank is the original-spec reservoir that forms part of the Taycan’s coolant system, responsible for managing coolant volume and pressure as the system heats and cools. Manufactured by Porsche to strict OEM standards.

Fits:
Porsche 9J1.1 Taycan 2020 - 2024

Diagram ref no 1

The coolant expansion/overflow reservoir for the Taycan’s coolant system. It collects and stores excess coolant from the closed-loop cooling circuit when temperature changes cause expansion. It also provides a visible coolant level reference and a refill point when topping-up is required.

This coolant tank:
• Accepts excess coolant as it expands under heat, preventing over-pressure in the cooling system.
•  Allows coolant to return to the system when temperatures drop, helping maintain proper coolant volume and pressure.
•  Provides a clean, secure housing that resists heat, pressure, and coolant chemistry - preventing leaks and degradation.
•  Maintains correct coolant level and system integrity, vital for thermal management of batteries, motors, and inverter cooling.

When to replace.  You should consider replacing the coolant expansion tank if:
•  The original shows cracks, discoloration, deformation, or leaks.
•  Coolant level drops unexpectedly without visible external leak - indicating internal crack or cap failure.
•  The tank becomes brittle, warped, or chemically aged due to coolant exposure and heat cycles.
•  You are restoring or servicing the cooling system, or performing maintenance/replacement of hoses, pumps or thermal components.

Related reference numbers
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9J1121407A

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