The Meyle 8E0 121 403 Coolant Tank is a direct-fit OEM-style expansion tank engineered for Audi A4 B6 and B7 platform models. Furthermore, it manages thermal expansion, maintains correct system pressure, and serves as the primary coolant fill point — with an integrated level sensor included for a complete, plug-and-play installation.
$18.00
The Meyle 8E0 121 403 Coolant Tank is a direct-fit OEM-style replacement engineered to restore dependable cooling system performance on Audi A4 B6 and B7 platform vehicles. Specifically, this tank performs three critical functions within the cooling circuit — it accommodates thermal expansion and contraction of coolant, maintains correct system pressure, and provides the primary fill point for the entire system. Additionally, this unit includes the integrated coolant level sensor, so the complete assembly installs directly without sourcing additional components. Because the Meyle 8E0 121 403 Coolant Tank is engineered to OEM dimensions, it fits using factory hose connections and mounting points without any modifications required.
Expansion tank failures follow predictable patterns, so recognizing the early warning signs helps prevent serious engine damage. First, a recurring low-coolant warning — even after refilling — strongly indicates a slow leak from the tank body or seam. Furthermore, coolant puddles or dried residue beneath the front of the engine bay confirm active seepage. A persistent sweet coolant odor after driving is another reliable indicator. Moreover, original tanks on B6 and B7 platform vehicles commonly become brittle or develop stress cracks from prolonged heat exposure and pressure cycling. In addition, a failed level sensor may trigger a false low-coolant warning even when the system is full. In more advanced cases, air enters the cooling circuit through the compromised tank, and consequently the engine runs hotter than normal.
OEM Reference: 8E0 121 403
Brand: Meyle — trusted European OE-quality replacement parts manufacturer
Includes integrated coolant level sensor for plug-and-play installation
Direct bolt-on fitment using factory hose connections and mounting points
Correct tank geometry for proper B6/B7 platform cooling circuit integration
Engineered to restore proper system pressure and coolant volume control
Before installation, confirm that all hose port positions and the sensor connector on the new tank match those on the original unit. Next, fill the tank to the MAX mark using approved Audi G12, G12+, or G12++ coolant only — never mix coolant types, as doing so degrades inhibitor chemistry and accelerates internal corrosion. After filling, run the engine to operating temperature with the cabin heater set to full heat, then recheck the coolant level once the system cools completely. Moreover, inspect all coolant hoses and clamps during this service and replace any that show cracking, softness, or swelling. Finally, verify that the level sensor connector is fully seated and clear any stored coolant-level fault codes before returning the vehicle to service.
Always verify fitment by VIN before ordering.
Cross Reference Numbers
8E0 121 403 A
8E0 121 403 F
| Weight | 1.1 lbs |
|---|---|
| Dimensions | 11 × 9 × 7 in |
| Year | Make | Model | Engine | Notes |
|---|---|---|---|---|
| 2002-2008 | Audi | A4 | 1.8L | |
| 2005 | Audi | A4 | 2.0L | |
| 2006-2008 | Audi | A4 | 3.2L V6 | |
| 2002, 2004 | Audi | A6 | 3.0L V6 |
The 06K 903 133AF is an OE-spec accessory drive belt tensioner assembly for select Volkswagen and Audi 2.0T applications. Engineered to factory specifications, this direct-fit replacement restores correct belt tension across all accessory drive components — no modifications required.
The 5Q0 122 291AC is the OE right-side coolant bypass line adapter (T-piece) used on select 2018–2023 Volkswagen and Audi MQB-platform vehicles equipped with a 2.0L engine and manual transmission. Positioned on the passenger side of the cooling circuit, it serves as the outlet adapter for the cooling system bypass line — a distinct application from the central water pump connectors used on the same platform. Always confirm fitment by VIN before ordering, as this part is transmission-specific.
The ABS Speed Sensor WHT003860 is a genuine-spec, OE-quality replacement for select Volkswagen and Audi models. It delivers precise wheel-speed data to your ABS, ESP, and traction control systems with a direct plug-and-play installation and no modifications required.
The ATE ABS Speed Sensor WHT003859 is a premium OE-quality replacement for select Audi and Volkswagen models. It delivers precise wheel-speed data to your ABS, ESP, and traction control systems with a true plug-and-play installation.
The Graf 06K 121 011C Water Pump is an OE-quality coolant pump engineered for select Volkswagen and Audi EA888 1.8T and 2.0T TSI/TFSI engines. This direct-fit replacement features a precision aluminum housing, correct impeller geometry, and a high-quality bearing and seal assembly for factory-spec coolant circulation and long service life. Includes gasket or O-ring for a complete installation.
