Engine Coolant
ED THOMAS
CONTRIBUTING EDITOR
How long-lived is long-life coolant? Each trucker's experience with antifreeze that's supposed to last a quarter-million miles or more may differ, but like anything made to reduce maintenance, long-life antifreezes are not maintenance-free.
For starters, there's the coolant's level. Virtually every truck's cooling system will lose some coolant over time, because connections and hoses will invariably leak a little. The average over-the-road truck loses eight to 10 gallons of coolant a year.
"That's a drop a mile," says Darrell Hicks, a sales and service representative with the Penray Companies. That's why drivers or mechanics regularly top off the surge tank with water and, we hope, anti-freeze.
When out on the road, most truckers regularly check under the hood. If they find surge tanks empty and no coolant in sight under radiator caps, what do they do? Most likely, they'll grab the nearest water hose and top off the system. Do they replenish the surge tank to the proper line ("hot" or "cold"), or just fill it up? If they fill it, they've put in too much and the excess will simply escape through the vent.
And the water should be clean and free of minerals. If not, waterborne contaminants will quickly deplete the antifreeze's protective chemicals and the contaminants will begin attacking the passages in the cooling system. How many truckers know if the water coming out of a hose is clean or hard? How many know what brand and type of antifreeze their fleets use?
If they're conscientious, drivers will buy a jug of antifreeze from a truckstop's store and pour in some of that, too. If they really care, they'll try to mix it 50-50 with water, like it's supposed to be. If they add no antifreeze, they dilute the coolant and its ability to guard against freezing and overheating is compromised.
So adding some antifreeze is good, but not if it's just any brand. It should be the same kind that's already in there. How many fleet managers tell drivers the brand and type of antifreeze used in their trucks? How many drivers ask their dispatchers what to buy and pour in? How many dispatchers know, or care? If put through to the shop, a driver should be able to find out such information. But how many go to that trouble?
Hicks says he's seen damage to engine parts, especially cavitation of cylinder liners and other innards, in fleets that have adopted long-life coolants. It happens because managers thought long-life means no maintenance. He recommends a thorough inspection of the system be done every 30,000 miles. Aside from looking for leaks, worn hoses and the like, it should include:
• Using a refractometer to check the coolant's freezing point, which should be down around 35 below zero F (and will be, if the coolant is the proper 50-50 mixture of water and antifreeze). The old ball-type hydrometer is not very accurate and should be avoided.
• Using test strips to determine the coolant's chemical composition, and therefore its ability to fight acids and other contaminants. Strips are the litmus paper type you handled in high school chemistry class, and turn colors to indicate condition. Strips and color charts are available from truck parts outlets and antifreeze suppliers.
Hicks says, "Regular checking of the coolant's condition is like oil analysis, and is necessary to take full advantage of the long-life products' potential. The guy who doesn't do it will end up with a stack of bills."
If you're not willing to take the extra precautions, then stay with regular antifreeze that's approved for your engine.
