Hi all,

 

I had a split silica bag 6 years ago on my 2.0tdi and it was all sorted and flushed under warranty. Over time though my expansion tank has become rusty coloured so I was wanting to remove and clean it inside.

 

What is the best way to do this to get rid of the rusty stain inside ? 

 

Cheers 

The simplest way would be to just replace the tank. There are plenty of OEM quality tanks available without needing to buy VAG. 

Unless the coolant has become contaminated again - or incorrect coolant has been used, there shouldn't be any staining of the tank.

Anti Freeze. 

Is actually Anti Freeze / Summer Coolant / Rust Inhibitor. 

50 minutes ago, Ootohere said:

Anti Freeze. 

Is actually Anti Freeze / Summer Coolant / Rust Inhibitor. 

So you think I could clean it with antifreeze itself ? 🤔

As per my post above, just replace the tank - you can get good quality OEM ones for around £15. Make sure the replacement is not 'Mit Silikat' Suggest getting a pair of proper (inexpensive) hose clip pliers - makes the job so much easier and useful for other hose tasks in future (like air filter replacement)

Thanks all, I'll need a new cap anyway so I'll see about a tank at the same time.

My plan was to soak it in vinegar in a bucket overnight to get rid of the rust stain.

I've added probably 5 litres over the past 6 months as things got worse.

I was hoping that might have replaced some of the dirty but when thinking about it the evaporated coolant would have left all the muck behind meaning so doing coolant wouldn't have helped.

I've seen on YouTube someone who disconnected the return pipe and fed that into a bucket whilst they added the coolant to the tank. That way it flushed through. Has anyone e tried that ??

Thanks

I'd suggest a full coolant change at the same time - in order to avoid air locks in the cooling system, it's worth considering vacuum filling (or similar) when refilling the system.