Im flushing my cooling system and putting in a 60/40 mix with distilled water, I was reading on the royal purple bottle of Purple Ice additive that "distilled water shouldnt be used in aluminum rads" any truth to this? my last flush was with distilled & i had no problems. thx boyz.

 

http://ls1tech.com/forums/general-ma...or-yes-no.html

 

I've used distilled in ALL of my vehicles and never had any corrosion issues. I also take whatever coolant length interval they recommend and divide it by 2 and use that for flushing system.

 

Distilled water can cause its own problems because it has such a low pH. Water will seek its own balanced pH, and when distilled water is placed next to aluminum, it leaches the minerals it wants from the alloy and black soot forms in the coolant. That's why silicates are put in aluminum-compatible antifreeze, they're sacrificial minerals that keep the soot from forming.
Very few modern antifreezes don't contain silicates, most pre-mix antifreeze contains distilled water.

I would follow Royal Purple's instructions, apparently their additive doesn't contain the sacrificial silicates.

 

Water PH is 7 by definition - neutral, neither acidic nor alkaline. The "leached minerals" are not from the aluminum but from the times that a non-distilled water was used and caused deposits in the cooling system.
Distilled water is a strong solvent and will dissolve gunk that is in the system. I am pretty sure it will not harm aluminum.

 

The distilled water should not be a problem as long as you use antifreeze, but be careful which antifreeze you select. I changed out my brass radiator for an aluminum one last spring and researched which antifreeze would work best in the new rad. Zerex G05 HOAT was the answer for me.

Here is a good link that covers all types of antifreeze and how they protect different metals.

http://www.geocities.com/dtmcbride/h...ntifreeze.html

It is worth a read.