After Monaco Technical Support advised me that they put Texaco Antifreeze 50/50 mix plus 2 quarts of Texaco Extender (Supplemental Coolant Additive [SCA]) in my engine at the factory, I purchased two test strip kits from Cummins. The first kit, p/n CC2602A, was to test the glycol level and SCA level; and the second kit, p/n CC2718, was to test the pH and level of chloride and sulfate. Everything tested fine with an SCA level of 2.2, which Cummins Filtration Technical Support (800-223-4583 opt 1, 4, 3) recommended that I add 16oz of DCA4 (Cummins p/n DCA60L). The 16oz bottle equates to 5 units of SCA, and because my system holds about 10 gallons that should add 0.5 to my SCA level bring it up to 2.7, which I'll go back and check in about a month or so.
Be careful when purchasing these test kits to note their expiration/use by date. The expiration date on the CC2718 kit is stamped on the top of the plastic bottle instead of on the package while the use by date for the CC2602A kit is stamped on the back of the package. For new coaches, it's really a waste of money to purchase the CC2718 kit, which is the most expensive at $17.00 for ten strips. The CC2602A kit was $6.12 for 4 strips, and the DCA60L was $5.13.
The ladies at Cummins Filtration Technical Support were great in bring the chemistry down to my level and egger to know my test results so they could compute and advise how much DCA needed to be added. They didn't know what the letters DCA stood for other than "(Something) Coolant Additive" even though DCA4 is their secret formula.
2007 Monaco Camelot 36PDQ
2009 Hyundai Sante Fe Toad