I've done quite a few cooling system services on vehicles before,
but I never gave much thought about coolant Ph.
Can anyone give me a quick lesson on coolant Ph?

-why it's important?
-what is the proper range
-how do you mantain proper Ph?

 

Extensive testing has shown that a coolant pH below 8.3 pH is not acceptable for use in engines due to its corrosive nature. The correct pH value should be maintained between 9.5 - 10.0 pH. Below 9.0 pH it is advisable to flush the cooling system and refill with a new coolant solution. If a coolant's pH drops below 8.5, it will become aggressive to ferrous metals (cast iron and steel), aluminum, copper and brass. If it increases above 11, it will become aggressive to aluminum and solder in a cooling system. Maintaining optimum pH in a coolant is a critical function of a quality coolant additive (SCA). It is important to use coolant additive package containing a pH buffer to insure the optimum pH range of the coolant. IF YOU ARE UNSURE JUST CHANGE YOUR COOLANT.

 

So is there any way to check this or do you just change your coolant every couple years and guess it's alright? I've read something about using half tap water with half purified when mixing the solution.
Brent

 

You can buy test strips at most auto parts stores. Or use pool test strips if you have a swimming pool. Ph is Ph.

 

In our lab I tested basic green coolant and the PH was above 12 which is alkaline. 7 is neutral and below 7 is acidic. Another reason NOT to use deionized water, its PH is around 6 thus neutralizing the coolants usefulness. Use Distilled H2O. Think its time to do some oil sludge tests in our muffle furnace with Delo,Rotella and synthetics.

 

Im not sure if its the same. In the trucking industry the cooling systems are tested to control electolisis. Any truck dealership should have the kits.
They sell the test kits with test strips. they also sell what they call DCA to give the right balance.