Chemicals that dissolve snow and ice also attack trucks. Salt spray corroded this aluminum fuel tank.
Chemicals that dissolve snow and ice also attack trucks. Salt spray corroded this aluminum fuel tank.

When we entered the 21st century, a well-equipped Class 7 or 8 truck chassis might have cost $90,000 to $110,000. With inflation, that might be $100,000 to $120,000 today. The EPA imposed ever more stringent emissions regulations in 2002, 2004, 2007, and 2010. What once cost $100,000 is now up to almost $130,000.

It makes sense more than ever to hold on to any performing asset as long as possible. For most producers, that means keeping your trucks operating properly for as long as you can.

To help fleet managers achieve this goal, The Maintenance Council (TMC) – now the Technology and Maintenance Council – hosted dialog between manufacturers, members of the Society of Automotive Engineers (SAE), and large fleet owners. This discussion began in the mid 1980s as a series of “Tomorrow's Truck” papers. As a result, our industry has fleets in which fuel mileage has improved by 40% to 50%, engines last hundreds of thousands of miles longer, and cabs can now look showroom new even after 10 years when properly maintained.

Truck cabs and bodies are better protected than ever. Manufacturers use galvanized steel and polymer paints to increase durability. Multi-part coatings have replaced enamels that once lasted only three to four years. Today, improved urethane base coat/clear coat systems, when properly maintained, protect against abrasion from sand and gravel and keep a high gloss for the life of the truck. Most paint manufacturers advise owners to polish trucks with products made for commercial vehicles at least yearly, preferably more often.

Concrete producers have long known the challenges of exposing cabs and bodies to corrosive cleaning chemicals. While fleet managers have reduced the use of muriatic acids on truck drums, they are quick to advise drivers to thoroughly flush any residue.

In addition to cleaning, a new corrosion villain has arisen to make preventative maintenance more challenging. New deicing chemical combinations (calcium- and magnesium- as well as sodium-chloride) and brines made snow removal more efficient. But they have a major downside. They are highly corrosive to trucks. They attack chassis, running gear, electrical systems, cabs, and cab hardware.

Prevention basics

It's important to know the effects these compounds have on trucks and what can be done to mitigate them and prolong vehicle life. Avoid touch-ups with automobile paint systems that don't have catalyzed basecoats. They're not tough enough for commercial service. Neither are most car waxes and polishes, which contain buffers against the ultraviolet rays that ultimately deteriorate all paints. Look for specialized protection designed for trucks.

Inspect door frames and hardware, hinges, linkages, support hardware, and fasteners for corrosion. Lubricate latches and handles to maintain smooth operation.

Salts and deicers are electrolytes that, with water, create conductive paths between dissimilar metals. Aluminum cabs on steel chassis are most vulnerable. Even a steel bolt can cause galvanic action and corrosion with aluminum components. Plated fasteners are covered with metals that resist corrosion.

Fiberglass does not corrode, but mounting hardware does. The key to maintaining long cab life is to find and break corrosive paths. When corrosion is found, inspect metals around the area. If necessary, disassemble the parts and remove all corrosion. If it is widespread, it may require sandblasting or cutting out and replacing the damaged metal.

Don't just reassemble. Try to identify the corrosive path, and then take steps to block it. This may require insulated bushings or gaskets to isolate non-structural fasteners. If fasteners must be torqued to specification, use plated fasteners rather than gaskets.

If you use coatings that can be applied over rust to neutralize it, remember that they are short-term corrections, not long-term fixes, like treating the symptoms rather than curing the disease. To minimize corrosion and maximize durability, some manufacturers are turning to chemical bonding and eliminating metal fasteners. Consult an experienced professional to make repairs to bonded surfaces.

Cabs have improved dramatically since 1985, when TMC members first presented users' ideas for “Tomorrow's Truck.” Since then, aggressive highway chemicals have increased demands on maintenance. TMC has a number of Recommended Practices on cab maintenance. They cover specifying, inspecting, selecting paint systems, preparing surfaces, and even guidelines for washing and cleaning. You can get the complete RP Manual, including both engineering and maintenance practices, free with a TMC membership. You'll also keep up to date on the latest best practices and training materials for your technicians.

For details, call 703-838-1763. Even if you don't join, buy the RP Manual. It's the best guide to maintenance you can get.

Paul Abelson is a former director of the Technology and Maintenance Council of the American Trucking Association and is on the Board of Truckwriters of North America.

CLICK HERE FOR THE WEB EXTRA ARTICLE: Protecting Your Assets Part II: Effects of corrosive chemicals on heavy duty trucks

Visit Abelson's Fleet Factors blog for more on preventing corrosion of brakes, chassis, suspensions and running gear.