Hydraulic Mining Shovel Oil Switch

Cat HYDOTM Advanced delivers long life for Cat and legacy Bucyrus hydraulic mining shovels

There are two groups of hydraulic fluid currently approved for use on Caterpillar’s hydraulic mining shovels (HMS). The first comprise Cat HYDO™ Advanced mineral oil based hydraulic fluids, available in viscosity grades SAE 10W, SAE 20, and SAE 30. The second is Cat Long Term Hydraulic Fluid HSS, previously named Bucyrus Long Term Hydraulic Fluid HSS, which is now being phased out. (Caterpillar acquired American original equipment manufacturer, Bucyrus, in 2011, with Cat dealer support provided for all legacy machines.)  

Both oils have a proven history, providing for 10 000 hour service intervals when combined with Cat S∙O∙SSM Services fluid sampling and oil analysis programmes. “Oil change intervals must be performed at 5 000 hours where S∙O∙S sampling is not adhered to,” explains Barloworld Equipment group product specialist, Reuben Pasha, “although this approach is definitely not recommended.” (Barloworld Equipment is the Cat dealer for southern Africa.)

Proper sampling means hydraulic oil S∙O∙S samples must be taken and evaluated every 500 hours. The recommended viscosity grade is SAE 20W for Cat and Bucyrus HMS units.

Compatibility studies were performed to confirm acceptable performance with an 80% mixture of Cat HYDO Advanced and Cat Long Term Hydraulic Fluid HSS. Therefore, for Bucyrus fleet owners, typically in the RH40 to RH400 model range, the transition to Cat HYDO Advanced is an easy and safe process. However, as Phasha points out, the correct system drainage procedures still need to be observed.

When changing a HMS from Cat Long Term Hydraulic HSS to Cat HYDO Advanced, at least 80% of the used fluid should be drained from the system. For most machines, this will require draining the hydraulic oil tank, suction header and suction lines, as well as the hydraulic cooler and hoses.

Correct drainage becomes even more important to note when machines transition to HYDO Advanced from a compatible, but non-Cat product. Then stricter measures need to be observed, with 90% of the used oil drained from the machine.

“Never mix incompatible oils as this can create sludge and precipitates that will prevent the system from operating correctly,” Phasha stresses.

If the commercial oil is deemed to be incompatible with Cat HYDO Advanced, a more thorough draining and flushing process will be necessary, working with Barloworld Equipment specialists for the changeover process. However, the end result will be worth it, as improved efficiencies and optimum mechanical health translate into measureable bottom line savings.