Primary Navigation
Home > Publications Directory > Technical Bulletins > Formula Determines Proper Glycol Levels For Adequate Boil Point Control
Formula Determines Proper Glycol Levels For Adequate Boil Point Control
Proper coolant glycol levels are necessary for adequate boil point control at high engine operating temperatures. Although pressure caps are now designed for up to 16 pounds of pressure and caps can raise a coolant's boil point by 2.7°F at sea level, a coolant that's properly formulated at 50% antifreeze can raise it another 12°F to 15°F.
Therefore, it is important to note, that when flushing a system, as much as one-third of the rinse water can remain in the engine block and passages diluting the new coolant's proper formulation. To correct a weak glycol level, first determine the actual percentage of glycol present using a refractometer. As an example, let's say the reading was at 40%. A level of 50-60% is necessary for adequate boil point control - 55% at higher than sea level elevations.
Correcting Low Glycol Levels
The following mathematical equation calculates how much coolant you need to drain and replace with coolant concentrate:
The amount of coolant to drain and glycol concentrate to add is equal to the system's capacity times the target glycol concentration minus the current glycol concentration divided by 100% minus the current glycol concentration.
| Gc | = | Current Glycol Concentration (%) |
| Gt | = | Target Glycol Concentration (%) |
| C | = | System Capacity (in Quarts, Liters, or Gallons) |
| D | = | Amount of coolant to Drain and glycol concentrate to add (in like units) |
The amount of coolant to drain and glycol concentrate to add is equal to the system's capacity times the target glycol concentration minus the current glycol concentration divided by 100% minus the current glycol concentration.
Example - Glycol Level Too Low:
The glycol concentration of a 40-quart cooling system is 40%. We want to adjust the glycol concentration to 50%.
| Gc | = | Current Glycol Concentration (%) | = | 40% |
| Gt | = | Target Glycol Concentration (%) | = | 50% |
| C | = | System Capacity (in Quarts, Liters, or Gallons) | = | 40 Quarts |
| D | = | Amount of coolant to Drain and glycol concentrate to add (in like units) | = | ? Quarts |
Drain 7 quarts of coolant and replace with 7 quarts of glycol concentrate. When adding glycol concentrate to correct low glycol levels, measurements can be simplified by rounding up. When adding water to correct high glycol levels, simplify by rounding down.
Correcting High Glycol Levels
| Gc | = | Current Glycol Concentration (%) |
| Gt | = | Target Glycol Concentration (%) |
| C | = | System Capacity (Quarts, Liters, or Gallons - use the desired units) |
| D | = | Amount to Drain and Amount of Water to Add (same units as C) |
The amount of coolant to drain and water to add is equal to the system's capacity times the current glycol concentration minus the target glycol concentration divided by the current glycol concentration.
Example - Glycol Level Too High
The glycol concentration of 10-gallon cooling system is 60%. We want to adjust the glycol concentration to 50%.
| Gc | = | Current Glycol Concentration (%) | = | 60% |
| Gt | = | Target Glycol Concentration (%) | = | 50% |
| C | = | System Capacity (in Quarts, Liters, or Gallons) | = | 10 Gallons |
| D | = | Amount of coolant to Drain and glycol concentrate to add (in like units) | = | ? Gallons |
Drain 1.5 gallons of coolant and replace with 1.5 gallons of distilled water. When adding water to correct high glycol levels, measurements can be simplified by rounding down.
Print this Technical Bulletin (PDF - 180K)
Quick Links
Top
News
POLARIS Laboratories® Expands into Central America
POLARIS Laboratories® is again extending its global reach with a new laboratory in Guatemala City. The expansion supports the company's global strategy for continued growth and is indicative of the strength and potential of the Central American market.
POLARIS Laboratories® Makes Inc. 5000 List Third Year in a Row
For the third year in a row, POLARIS Laboratories® has been named to Inc. Magazine's List of 5000 Fastest Growing Privately-Held Companies in America.
Training
Nashville
Cooling Systems Maintenance
March 6, 2012Nashville
Oil Analysis
March 7-8, 2012Houston
Cooling Systems Maintenance
April 17, 2012
Tradeshows & Conferences
UMA Motorcoach Expo
Long Beach, CA
February 8-12, 2012PepsiCo Summit & Tradeshow
San Antonio, TX
February 13-16, 2012
Secondary Navigation
