Severe Service Maintenance: Undercarriage Care

Perhaps the most vulnerable part of any apparatus is its undercarriage and suspension. Frames, springs, tires and related components are critical maintenance areas for apparatus used in severe conditions. It's where the proverbial rubber meets the road...


Perhaps the most vulnerable part of any apparatus is its undercarriage and suspension.

Frames, springs, tires and related components are critical maintenance areas for apparatus used in severe conditions. It's where the proverbial rubber meets the road, and also the place that is most subjected to all the crud and dirt the elements can sling at them.

Rick Suche is president and owner of Fort Garry Fire Trucks Ltd., an apparatus builder in Winnipeg, Manitoba, building a full line of emergency equipment for all of Canada with some apparatus making their way into the United States and around the world. His trucks are in service in some of the most extreme areas of the planet, including the Arctic.

"People look at our trucks and think we're building tanks," Suche said, noting apparatus endurance for extremes starts with solid apparatus construction. Fort Garry trucks are constructed of 5083 saltwater marine-grade aluminum to stand up to the rigors of what is essentially a constant saltwater spray, Suche said, adding the company also paints all surfaces and seals seams. To maintain the integrity of the body and prevent corrosion, Suche recommended the surfaces be kept cleaned, covered with paint and seams sealed.

Fort Garry also uses grommets and rubber seals where wires intersect with metal frames and around pump intakes and discharges to keep dust and water out and wires from chaffing, Suche said. "The big thing is to keep things clean," he said.

Suche said spring shackles, wheel wells and other places where road grime can accumulate must be cleaned regularly. Some of the trucks built at Fort Garry never see paved roads their entire service lives, so keeping them clean is paramount to longevity, he said.

Suche has been in the fire service for 30 years, serving as a volunteer firefighter and working as the president and owner of Fort Garry, a business established in 1919 and acquired by his father in 1945.

Suche said that because his company knows the trucks they build will be in some of the most extreme environments in world when it comes to corrosive road treatments, the company uses a heavy undercoating. He recommends departments maintain that undercoating with routine oil undercoating once a year, if possible.

Road treatments can be just as bad in Minnesota where General Safety - Rosenbauer America builds apparatus. Steve Reedy is the vice president and general manager of the General Safety division of Rosenbauer America. He's been in the fire service for 38 years and a firefighter and a chief during his career. His secret to preventing corrosion is the use of dielectric grease, a non-conductive silicone grease designed to seal out moisture and preventing corrosion on electrical connections.

"Apparatus in these parts can be driving in what amounts to a constant salt spray," Reedy said. And, while most electrical connections should be routed through bodies and channels, some are out and exposed in the undercarriage and subjected to the elements.

Apparatus are electrical creatures with lots of wires and lots of electrical components that can be damaged by corrosion and, consequently fail. Therefore, care of wiring is critical for apparatus subjected to severe service, Reedy said.

For example, tilt-cab apparatus, equipped with electric motors to raise and lower them, can experience shorts that can cause the cabs to rise while driving, Reedy said. An electrical bridge of salt and crud and be created between the tilt-cab motor and the solenoid that operates it, creating a contact that engages the tilt at any time.

"That can be a dangerous situation," Reedy said, noting that it can be avoided by cleaning the underside of the truck, particularly the motor and connections, which are often located under the trucks in areas that can accumulate crud.

John Marvin is General Safety's service manager and a National Institute for Automotive Service Excellence (ASE) Master Mechanic and an EVT Master as well. He stresses the importance of keeping apparatus clean on the underside.

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