COOLING MAINTENANCE TIPS
Studies show about 40 percent of engine maintenance is related to cooling system failures. The thing is, it needn't be that way. "Cooling system failures are virtually 100 percent preventable, but you need to maintain coolant the way it was designed to be maintained," says Dean Swick, OEM sales and account manager for Penray.
1. Know what type of coolant is in the engine and what you need to do to maintain it. Even extended-life coolants are not "fill and forget." The freeze point needs to be checked at least once, preferably twice, a year, and a visual inspection can determine whether further testing should be done for dilution with other types of antifreeze. Putting the right type of coolant in at top-off will ensure your engine is protected and you get all the benefits of organic formulas. To make this easier, standardize on one coolant.
2. If you're going to use traditional inhibitor technology, consider using fully formulated coolant rather than relying on your technicians to be chemists.
"I've told people this for a long time," says John Clevenger, director of global products for Cummins Filtration. "You wouldn't go out and buy a base oil, buy a separate additive pack and tell your guys to mix it in. Why take that approach to the coolant system, which touches every system – oil, fuel, exhaust gas recirculation – and can impact every one of those systems?"
Jim Roberts, technical service manager for Shell, reports that two of the biggest problems his company sees when looking at used coolant samples are over- or under-concentration of the antifreeze in the coolant system, and over- or under-concentration of SCAs, primarily over-concentration.
"People hate the concept of buying water," Roberts says, "so they think they're getting a better deal buying concentrate and mixing it. When you're buying a 50/50 premix, you always know you're putting in the right amount of coolant with the right amount of water, and it's good water, and you're always within a few percentage points of where you should be on your concentration.
"When we've converted fleets over to a 50/50 mix, some of these fleets would have 80, 90 percent antifreeze in their cooling systems because they kept topping off with concentrate." Too many silicates can cause silicate gel, or "green goo." Too much nitrite can lead to problems with your radiator, such as solder bloom, different types of attacks on aluminum. "It's like when you keep putting too much sugar in your tea, it's going to fall out to the bottom of the glass. In your truck, the bottom of the glass is the water pump and radiator. Those solids collect down there and cause water pump seal wear and plug your radiator."
3. Use a coolant filter. With the advent of extended-life coolants that don't need SCAs, some fleets and even OEMs have stopped using coolant filters, believing the primary purpose of the filters is to add time-release chemistry to the coolant rather than actual filtration. Filter manufacturers say that's a mistake.
"The coolant filter is on there because the coolant system has about five times the flow rate of your oil system," Clevenger says. "It's there to take out core sand, rust, corrosion particles, rubber from the pumps, all kinds of things going on in the cooling system, because all that creates wear."
Clevenger says problems such as water pump failures and thermostat failures can often be traced to contamination that a filter could have prevented.
In fact, he says, coolant filters may be more valuable than ever with the 2007 engines. "When you increase the cooling system size, with larger radiators, bigger pumps, an EGR cooler, now you've got more seals, more soft metals, all kinds of things that can contribute to particulates in the cooling system."
While the physical size of most coolant filters has remained about the same, says Brent Birch of Champion Labs, makers of Luber-finer filters, many offer greater contaminant holding capacity than in the past, using specialized synthetic materials in the filter element.
4. Consider using coolant analysis, just like you do oil analysis. Polaris Labs, which does oil, fuel and coolant testing, says testing coolant twice a year at a lab can help prevent the large number of engine failures that are attributed to cooling system problems. For instance, in addition to determining things such as proper freeze point and additive levels, a coolant analysis program may identify problems such as electrical ground problems, combustion gas leaks, air leaks and localized overheating.
