So what is the proper ph of coolant on my Cummins engine
Do not know what the pH level should be, but I use these test strips. I am still running green antifreeze. Amazon.com: Fleetguard Coolant Analysis Test Kit CC2602A: Automotive (https://www.amazon.com/Fleetguard-Coolant-Analysis-Test-CC2602A/dp/B002TQD2KI)
Rick,
You will need to tell us what coolant you have. Proper pH is different for the old-generation "Low silicate for diesel coolant with added SCA" and the new-generation OAT-based coolant.
And if the old generation, if it is low on SCA and you add more to bring it up to the proper concentration (test strips) that will raise pH (less acidic).
Test strips are specific to the antifreeze you are using.