Volvo 670 Cummins Coolant issue

Hi all. Driving 2007 Volvo 670 with Cummins. 1.25m miles. Woke up yesterday morning to red triangle and low coolant warning. Top coolant hose had cracked while idling at night. Changed hose and dropped 3.5 gallons of coolant into reservoir. Drove 600 miles no issues. Today when starting truck got low coolant sign again. No leaks that I could find. Checked reservoir and saw coolant was on low side, added appox 3/4 gallon coolant to get to max cold line. After warming up engine coolant is almost to the cap. Overflow is empty, will it just level out or am I going to have to try to drain main tank? Any suggestions?