Audi A8 A8 Quattro S8 Radiator Overflow Bottle - 1AROB00038

Our coolant overflow bottles are some of the highest quality replacements on the market!

This radiator coolant overflow tank has been designed to replace the original design.


  • Direct replacement for originals that are cracked or broken
  • Replaces dealer part numbers: 4D0 121 403C, 4D0121403C
  • Strengthened and redesigned in the vulnerable areas of failure
  • Plastic construction
  • Commonly called "Coolant Overflow Tank or Reservoir, or Expansion Tank" by Audi
  • Does NOT include the Cap
    • Buyer will need to reuse original cap

Now you can buy a high quality coolant reservoir that is built to strict quality control standards. REPLACE your broken or cracked one now with this great fitting Radiator Overflow Bottle.

Lifetime Warranty

This item is backed by a Limited Lifetime Warranty. In the event this item should fail due to manufacturing defects during intended use, we will exchange the part free of charge (excludes shipping charges) for the original purchaser. Please keep your invoice for proof of this warranty.

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Vehicle Fit

  • 1998-1999 Audi A8 Radiator Overflow Bottle
  • 1997-2002 Audi A8 Quattro Quattro Radiator Overflow Bottle for Models with V8 4.2L
  • 1998-1999 Audi A8 Quattro Radiator Overflow Bottle
  • 2003 Audi A8 Quattro Quattro Radiator Overflow Bottle for Models with V8 4.2L
  • 2001-2002 Audi S8 Radiator Overflow Bottle
  • 2003 Audi S8 Radiator Overflow Bottle

This part replaces:

  • OE # 4D0 121 403C
Only 1 left in stock
Part #: 1AROB00038

Ships Same Day for orders placed by 4 P.M. ET