A recent client consulted me about the hydraulic oil turning black, smelling bad and depositing varnish in the Hitachi EX5600 mining shovels he is responsible for. These are BIG diggers. Twin Cummins QSK50s with 4 main pumps (250 GPM) on each engine. Bucket capacity is 40 tons. And a 240 ton dump truck is loaded in 6 passes, in around … Read more
Why The Hydraulic Tank is NOT an Oil Cooler
During a recent conversation I had with a member who builds hydraulic power units, this observation was made: “Oil coolers are generally resisted by customers because of initial cost and maintenance, so fitting a bigger reservoir, when possible, is often the preferred solution.”
I recall coming across the very same resistance when I was building hydraulic power units for end-user … Read more
Another Reason Why Pump Suction Strainers Shouldn’t Be Installed
I recently came across an article describing a failure that occurred on a hydraulic machine during the last northern winter. The extreme cold had caused the water present in the hydraulic oil to freeze on the surface of the installed suction strainer. When the hydraulic system was started the ice-clogged suction strainer imploded and the resulting debris destroyed the hydraulic … Read more