Any debris blocking airflow through the radiator or wrapping around moving parts should be removed. Of course, operators should report, immediately, any damage that threatens safety or the health of the machine.

Preventive maintenance

Most wheel tractor-scraper models have daily service recommendations that specify components to be greased. Auger equipped scrapers and elevating scrapers have several additional lubrication requirements that open-bowl machines don’t have. Daily maintenance procedures can be performed by properly trained and equipped operators or by service technicians. Similarly, the fuel system water separator and fuel tank water and sediment should be drained daily.

Every 50 service hours or weekly, the bowl lift cylinder bearings and the hitch should be lubricated. At 250 service hours, oil samples — engine, transmission, and hydraulic — should be taken. Prompt oil analysis and reporting can help catch a developing problem before components are damaged. At 500 service hours, a cooling system coolant sample should be taken and analyzed.

Five hundred hours marks the point of several filter changes. Engine oil and filter are to be changed at that interval, as is the fuel system filter. The hydraulic oil filter and transmission oil filter also are to be replaced at 500 hours. A less common, but no less critical, preventive maintenance function at 500 hours is the cushion hitch (accumulator) pressure. The cushion hitch is filled with nitrogen and, effectively, dampens bouncing and loping as the machine travels.

At 1,000 service hours, the transmission oil must be changed. At 2,000 hours or one year of service, the oils should be changed in the differential and final drives, the hydraulic system, and the wheel bearings.

A sometimes overlooked aspect of scraper operation and maintenance is the selection and maintenance of Ground Engaging Tools (GET). Several options are available to optimize the machine for different material types and loading conditions. GET options include standard, serrated, and abrasion-resistant material. Most are reversible to provide long life and reduced operating costs.

With proper equipment selection, attention to detail during inspections, and strict adherence to preventive maintenance guidelines, operations can achieve low-cost, high-production results from their wheel-tractor scrapers.

Mark Sprouls is a mining writer who has worked with and within the industry for more than 35 years. He is based in Tucson, Ariz. Information for this article is courtesy of Caterpillar Inc.

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