Originally Posted by cheezit

the trucks are very well know to leech sand back into the cooling system. Im about to do mine for the first time and except to see a little bit come out. the vc9 just removes the iron deposits though. A good cooling system cleaner for everything but rust is a 1/4 bottle of simple green or liquid cascade dishwasher soap. so I would flush with vc9, then run a little simple green to get rid of the remaining vc9.

as far as how often well im gonna say every 30k or so. But its free for me I just do it at the shop.