Because it’s part of the cooling circuit returning coolant to the reservoir, damage (cracks, leaks, disconnections) can cause coolant loss, low coolant warning, or even overheating if not addressed.
Fits
Audi Q7 (4LB) 03.2006 – 08.2015
Audi A5 B8 Coupe (8T3) 06.2007 – 01.2017
Audi A4 B8 Saloon (8K2) 11.2007 – 12.2015
Audi A4 B8 Avant (8K5) 11.2007 – 12.2015
Audi Q5 (8RB) 11.2008 – 04.2019
Audi A5 B8 Convertible (8F7) 03.2009 – 01.2017
Audi A4 B8 Allroad (8KH) 04.2009 – 05.2016
Audi A5 B8 Sportback (8TA) 09.2009 – 01.2017
Audi A8 D4 (4H2, 4H8, 4HC, 4HL) 11.2009 – 01.2018
Audi A7 Sportback (4GA, 4GF) 10.2010 – 11.2019
Audi A6 C7 Saloon (4G2, 4GC) 11.2010 – 09.2018
Audi A6 C7 Avant (4G5, 4GD) 05.2011 – 09.2018
Audi A6 C7 Allroad (4GH, 4GJ) 01.2012 – 09.2018
Volkswagen Touareg II (7P5, 7P6) 01.2010 – 12.2018