Why Rigorous Testing and Preventive Maintenance are Crucial for Summer Cooling System Health

During summer, high ambient temperatures can push engine cooling systems beyond their limits. Proper coolant management and preventive maintenance are essential to extend system life and keep engines running efficiently.

Regular field testing at each preventive maintenance interval verifies that cooling components function correctly, glycol concentration stays within the optimal 50‑60 % range for boil‑point control, inhibitor levels protect metals, and the pH remains within OEM and coolant‑manufacturer specifications for corrosion control.

Why does coolant formulation matter? A 50/50 mix raises the coolant’s boiling point to 225 °F at sea level—just the minimum for modern engines that run between 225 °F and 250 °F. Each additional pound of pressure adds about 2.7 °F, so a 14‑lb pressure cap elevates the boiling point to roughly 263 °F. A faulty pressure relief or low glycol level drops the boiling point back to engine temperature, leaving the system vulnerable.

A 40 °F buffer protects against boiling. When coolant boils, glycol breaks down into oxalic acid, producing a dark brown‑gold “burnt” coolant with a distinctive odor. This varnish coats internal parts, hampers performance, and is difficult to remove. Thorough flushing, cleaning, and correcting hot spots are required before re‑introducing coolant. Routine coolant strip tests during PMs keep operations smooth and prevent costly downtime.

Quarterly laboratory analysis can uncover heat‑induced problems before catastrophic failure, enabling maintenance teams to tailor testing schedules. For detailed procedures, download the Technical Bulletin PDF (62 KB).

Polaris Laboratories LLC is a leading provider of oil, fuel, coolant, and water‑based fluid analysis. With roots in Indianapolis (since 1999) and labs in Houston and Salt Lake City, Polaris combines state‑of‑the‑art equipment, experienced technicians, and a national sales & service network to help customers save millions in lost production and equipment replacement. Learn more at www.polarislabs1.com.