Coolant maintenance activities typically increase in the September/October timeframe and again in the March/April timeframe. Maker sure you are prepared for the weather changes by ensuring your cooling system is optimal.
Dan Holdmeyer
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When it comes to basic maintenance practices, the coolant system and its fluids are one of the most important components of your trucks. As you are probably aware, coolant maintenance activities typically increase in the September/October timeframe and again in the March/April timeframe. 听The increase relates to preparing for the weather changes and ensuring your cooling system is optimal before entering either the cold winters or hot summers. Before performing a check on this part of the vehicle, make sure that you think about safety first by ensuring that your truck is parked and secured in place with a lock out tag out if applicable. Ensure the cooling system is at a workable temperature鈥攂elow 100掳F and take precautions when opening the system because the system is under pressure. Now you are ready to get started.
Type of Coolant Used
Before you begin, make sure you know your coolant product, including product type, color, etc. Because coolant color is not necessarily indicative of general type, the TMC RP 351 Guidelines for color standardization of engine coolant/antifreeze indicate that green coolant is typically automotive grade, pinkish/purple is generally fully formulated or heavy-duty grade and red is generally heavy duty, extended life
It is important to note that automotive grade coolants are generally not recommended for heavy duty applications because they do not contain sufficient additives for liner cavitation, corrosion control or hard water anti scale protection. An automotive grade coolant does not meet ASTM D-6210 unless supplemental coolant additives (SCA鈥檚) are blended into the coolant prior to filling or topping off the cooling system.听 For simplicity, the automotive grade coolant (presumably pretreated with SCA鈥檚) and fully formulated heavy-duty coolant are referred to as 鈥渃onventional鈥� and the heavy duty extended life coolant are referred to as 鈥渆xtended life鈥�.
Fluid Check
Visually inspect the coolant color and coolant level in the overflow tank. Make sure it is clear and free of haze, debris and oil as well as free of unusual or foul odors. Your coolant level should be at the full cold level. If the coolant is black or brown or contains visible contaminates then the coolant should be replaced.
Test for the freeze point using a refractometer and verify that it is approximately -32掳F to -37掳F鈥攖he typical range for a 50/50 prediluted coolant; however, if the freeze point is -12掳F to -60掳F, it is an acceptable range but a correction may be needed. Outside of this range, the coolant should be replaced, presuming a 50/50 is in use. If PG (propylene glycol) coolants are used then a refractometer with a PG-based freeze point scale and a freeze point adjustment chart for PG based products should be used.
If adding water is necessary, it is recommended to use deionized or distilled water. It is not recommended by the heavy duty OEMs to use a concentrated coolant without water as the complete cooling system solution. Well water, city water, etc. may contain elements and minerals that may cause cooling system issues if they exceed set industry acceptable limits.
Fully Formulated
It is important to maintain the SCA level as this provides the protection for all of the components of the cooling system. Test strips are a fast, easy and accurate way to determine the SCA level and a good alternative to laboratory testing. Ensure that the test strip used matches the type of conventional coolant being used. For example, TMC RP 329 Type A and B will test for conventional coolants using (A) nitrite for liner cavitation protection or (B) a combination of nitrite and molybdate for liner cavitation protection.
Different types of test strips on the market meet the different types of traditional coolants. SCA level should not be under or overtreated. SCAs can be added to the cooling system in various ways鈥攍iquid or filter. SCAs in a liquid form can be added directly to the cooling system per the manufacturer鈥檚 specific directions. SCAs may also come in a coolant filter; sometimes referred to as a water filter. SCA coolant filters come in a TMC RP 329 type A or B formulation. SCA coolant filters come in a standard service interval as well as an extended service interval (ESI).听 Standard service filters are designed to be replaced at the OEM recommended preventative maintenance interval with service intervals up to 25,000 miles. ESI filters will need to be replaced at the OEM recommended interval, which is annually.听 If testing the coolant indicates a low SCA level, then liquid SCAs may be added to boost the SCA level or in the case of a standard filter, replacement may remedy the low level.
Now that we鈥檝e talked about coolant color and levels, part 2 of this article in the November issue will discuss the life of your coolant and some additional inspections you may need.
Dan Holdmeyer is Industrial & Coolants Brands Manager, STLE CLS and OMA I Certified, of North America Lubricants for Chevron Products Company (Louisville, KY). Chevron is a world leader in coolant technology with commercial sales and OEM relationships that span the globe. Dan can be reached at (440) 708-8860 or via e-mail at [email protected].
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