"When traveling, the undercarriage components will naturally increase in temperature," notes den Hoed. "If the machine enters water on a jobsite, there will be a rapid change in component temperature (expansion/contraction). This is very hard on moving joints."
Working in these more severe applications may require more frequent maintenance and greasing. "A machine working below the water surface or in heavy lifting applications may put it beyond its maintenance intervals and greasing intervals will need to be changed," says Metzger. "Installing an auto lube system will increase the initial cost of the machine, but in the end [it can] reduce the maintenance cost over the life of the machine."
Excavators used in demolition are working in very severe conditions with severe-duty attachments. "This type of work puts a lot of stress on the undercarriage because of the breaking and loading of heavy and unbalanced loads," Metzger says. "In addition, because the attachments... are working at capacity most of the time, and the hydraulic temperatures tend to be higher, the hydraulic system will need to be maintained more often. Heat is the biggest enemy of any hydraulic system.
"Because this type of work requires heavy loads," he continues, "this will also put a lot of stress on the structure of the machine and cause pin and bushing, boom and arm fatigue that you would not see in normal operation."
Selecting the right machine and tailoring your preventive maintenance program to the application can help you overcome such negative effects.
"Overall, if the machine is designed and sized right, and the operator does the daily checks, there aren't many applications where an excavator can't work and perform efficiently with great reliability," says Hall. "When you've spent the dollars that a large excavator costs, spending a few dollars looking after your investment pays dividends in terms of productivity, residual value and operating costs."
A Daily Commitment to Service
In Marcus Thompson's line of work, preventive maintenance is critical to keep machines running smoothly. Thompson works with his father, Hiram, his uncle, Glen, his brother, Tyson, and his cousin, Paxton, at Thompson Wrecking, a third-generation demolition/asbestos abatement firm headquartered in Augusta, GA.
The types of jobs the company performs can be tough on excavators. For example, crews are currently tearing down a hospital in Georgia, as well as an incinerator plant in South Carolina that was used to burn medical waste.
"We try and compensate for [tough jobs] by putting a good preventive maintenance program in place," says Thompson. "We have a couple of full-time mechanics who keep our excavators serviced."
Frequently changing air filters is one of the most important things the company does do to keep the engine clean, he adds. "It helps the oil last longer so we don't contaminate the engine. We're getting a lot of trouble-free hours for the maintenance we do," he states.
Air filter maintenance includes a change-out every other time the oil is changed. However, the filters are checked every day during the pre-inspection program conducted before the engines are fired up. Typically, they are blown out at least two to three times a week because of the dusty working conditions.
Making sure that all moving parts are greased is another key component in the maintenance program. "There are so many moving parts," says Thompson. "There isn't a machine that gets cranked up and used until the operator has gone over every grease fitting. If we keep them greased regularly, the machines will last a long time. We've been down that road before and we haven't always placed as much importance on maintenance as we should. But when you start to spend a lot of money in fab shops to have things repinned, it adds up. A $2 tube of grease can save you thousands in the long run."