Replenishment tank for coolant leaks

Hello.

this week had to change the refill container of my A8, after it had become porous at the top of the connection for the small hose. Looks like I've seen it happen more often. I had been wondering all the time about the coolant streaks on the outside of the container, but I had pushed that to refill the container. Now this week the warning lamp lit and, look, the container was half empty. Then up at the connection of the little tube played around and already a fountain almost splattered into my face. Emergency repair tests with soldering iron etc were useless, so called Audi. They even had one. Who cares, the part comes complete with new dealer, has the part number 4D0 121 403 C and costs 24 Euro incl. Tax. The installation is quite simple:

- release overpressure (if still available) by turning the lid on
- Empty suction container (e.g. with hose, suction liquid and in a bottle etc. I had to run, and I had to go to my house. 1.5 liters inside
- Unscrew old containers (I think they are 3 screws, one still holds a black plastic cover at the spring dome)
- Pull out the container, pull out the plug for the encoder and hold the container so high that the hose connection is the highest point in the cooling system below.
- Dissolve hose clamp and remove hose
- Insert hose on new container, tighten clamp, plug back into encoder
- Mount the container, put small hose on top
- Replenish coolant
- Run the engine and maybe. Refill coolant
- to make sure that there is no air in the system, you can open the venting screws on the heating hoses again

Ready.


Greetings,

Matthias