Q: What is the proper chemical SCA (supplemental coolant additive) concentration for my engine?
A: A chemical concentration of 1.5 - 3.0 UPG (units per gallon) should be maintained in your cooling system at all times.

Q: Is your SCA DCA4 inhibitor compatible with Nalcool/Penray additive?
A: Cummins Filtration's SCA is compatible with Nalcool/Penray chemicals. When testing a mixed coolant for SCA content, always use Cummins Filtration's CC2602 test kit for proper chemical concentration measurement.

Q: What is the difference between DCA and DCA4?
A: The difference between the two forms of DCA is the chemical makeup. DCA is a borate/nitrite based additive. DCA4 is a phosphate, nitrite and molybdate based additive. DCA4 is recommended by many OE manufacturers, including Cummins, Navistar, Ford, John Deere, and others.

Q: My cooling system is contaminated with rust, scale, oil or grease. What is the solution for these problems?
A: Cummins Filtration's cleaner Restore Plus™ eliminates rust, scale, oil and grease with its special acid-based formula.

Q: How much DCA4 should be added at service intervals?
A: It depends on system capacity. If no test results are available, use 1% to 2% of liquid additive or 0.1 to 0.2 units per liter of coolant.

Q: What is the probable cause of nitrite leaving the coolant while molybdate remains at normal level?
A: This condition is caused by excessive exhaust gas leakage into the coolant and /or topping off the additive package with some other nitrite-free additive.

Q: My cooling system is contaminated with silicate gel. Can I remove this with plain water?
A: No. Cummins Filtration recommends using its alkaline-chelating cleaner RESTORE.