Early PM can pay big dividends

Catching problems with oft-overlooked maintenance items can pay big dividends. Timely replacement of these problems can make great contributions to robust preventive maintenance programs, reducing thousands of dollars a year in operational costs by helping you avoid breakdowns and provide better service to your customers.

CHARGE AIR COOLER. The CAC is the most overlooked item on a Class 8 tractor. It sits in front of the radiator and looks like a radiator. In essence, that’s what it is. It is designed to cool superheated air from the turbo before it gets into the intake manifold for more efficient combustion.

Seeing a water leak from a radiator is easy, but your CAC needs to be pressure-tested to find leaks. You can make or purchase a test kit, or have it done at any engine shop. Each engine manufacturer sets a limit on how much CAC pressure loss is acceptable, usually 5 to 7 pounds in 15 seconds.

But given the immediate drop in fuel mileage a leaky CAC causes, I’ve found it makes sense to replace a unit that leaks just 2 pounds in 15 seconds. At that level, at 2,500 weekly miles at 6 mpg and $2.75 per gallon, you’d be losing $88 a week. You’ll spend $1,000 to $2,000 to get the CAC replaced with a good aftermarket cooler. Your breakeven comes in less than six months, and your return on investment will be substantial.

This doesn’t take into account other problems associated with a failing CAC, which can include engine power loss, exhaust manifold failure, premature piston ring and valve failure, elevated engine coolant temperatures and turbocharger failures. I recommend testing the CAC every three months or anytime you see a drop of 0.3 to 0.4 mpg that can’t be explained any other way.

CRANKSHAFT DAMPER. Most engine shops will tell you this doesn’t need to be replaced. They don’t even replace it on an in-frame. This is a mistake.