how do I clean coolant reservoir ???

[djb]

Using pennies or marbles has an obvious risk.

The usual way to clean tanks like this is to put in something that will dissolve -- sugar or salt -- and shake vigorously. Pour out what you can, then flush the tank throughly.

Coarse water softener salt works great, but you don't want "rock salt" with impurities that won't dissolve.

 

[Loobed]

Originally Posted By: George7941
Did you ever find out what generated the residue in the first place? There must have been an underlying cause. Some possibilities are
1)Stop-leak additives
2)tap water instead of distilled water
3)engine oil leaking into the coolant
4)low coolant level

Hopefully, the underlying cause has been fixed.



I don't know how it started, but it started with dexcool about 2003, that's why I started changing the coolant so many times. I had the system pressure checked and nothing is wrong. No leaks of any kind.

 

[Loobed]

Originally Posted By: Anies
Can try amazon.com and buy a replacement for 90% off(genuine A/C Delco). Cost me $23 shipped compared to $90 at GM parts direct and over $110 at the dealer. That grime is tough as nails to clean up.



$23 is a good price. The cheapest I found was about $60.

 

[JustinH]

Rockauto sells replacement surge tanks. I agree to buy a new cap also.