[j cAT]

dexcool is required so gm says in this engine. this is to protect the components used for seals as well as the aluminum corrosion protection..

with dirty tap/well water that has metals and corrosive chemicals this creates a conductive SOUP ... THEN THE LEAKS START..

not using the higher concentration adds to all of this...

using non dexcool , reacts with the leftover dexcool to cause a blocking mess in the heatercore / radiator..

I change this coolant 3-4yrs and with distilled water it still LOOKS GOOD..

with boat engines draining the block is step one , step 2 is ADDING full strength coolant until it flows out..

I have the mcm 470. with this I use 75% silicate coolant with 25% distilled water...only had to do that front cover water pump once..

1979 engine..ran great this summer no problems !