A CAT 777D operating at a northern Alberta oil sands mine suffered a torque converter failure. This failure can be particularly catastrophic because the torque converter, braking and hoisting systems share the same hydraulic oil.When a torque converter failure occurs, a significant amount of metal contamination isreleased into the system and quickly circulated through all the circuits. The entire contents of the hydraulic system (405L or 107 US gallons) can circulate in approximately 1 minute, so contamination spreads quickly causing damage and accelerated wear to the brake and hoist components.

Following the failure, the hydraulic tank was drained, and all 4 Mag-Shield® were removed and weighed before cleaning and analysis. It was determined that 1.717kg (3.78 lbs) of material was captured by Mag-Shield® which would have otherwise flowed throughout the system and caused additional damage. Mag-Shield® made cleaning the hydraulic system faster and more effective. Post failure clean up is made possible as Mag-Shield® continues to clean residual contaminants from the system when the truck is put back into service. Follow-on failures were mitigated, and significant savings were observed by the truck owner.

Additionally, a sample from the dirty Mag-Shield® was submitted to SEMx Inc. for scanning electron microscopy analysis which determined a captured particle distribution of approximately 57% between 5μm and 40μm (these may not be captured by CAT Regular Efficiency filters), and approximately 26% of the captured particles were under 5μm (these particles may not be captured by CAT Ultra High-Efficiency filters). Unlike OEM filters, Mag-Shield® were able to capture and hold these ferrous particles, stopping them from circulating further throughout the system. OEM filters were not effective at removing smaller sizes of particles or simply plugging up with large volumes or contamination, forcing the system into bypass operation.