best way to flush out old coolant??
 

my question is what size is the coolant block drain plug on the starbord side of the block ??? looked like it might be a 1/2 extension but tried it but its bigger?? maybe torx or 3/4 extension might fit?? anyone know the easiest way to flush and get all old coolant out??



my seals that connect the heat exchanger to the block leaked out oover winter, i guess its a common problem 2002 and older. when it gets cool the seal shrinks and drains about a gallon out ;) the never part # seal is made a little different has a extra rib inside where it seals agains the pipe comming out of the h/e . 9$ each went ahead and replaced both easy as hell just gave me a reason to flush the coolant that says should have been done after 5yrs anyways

Pull the plug or a hose and let it drain. If your really wanting to flush the block it's no different than a radiator, but I'd just add new coolant myself. I sure wouldn't use Dexcool. I'd go get CAT extended life.

already bought 6 gallons of the merc pre mixed stuff which is dexcool i guess. 12$ gallon

i just need to figure out what kind of tool it takes to pull the plug

the more i look at it it kinda looks like a huge allen someones got to know