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
Tag Archives: hydraulics maintenance
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
The Top 2 Causes of Hydraulic Vane Pump Failure and How to Avoid them
One of our members wrote to me recently regarding the following problem:
“Recently, we bought a used hydraulic power unit (15HP electric motor directly coupled to a vane pump). A high-pitched, clicking noise is generated when the unit runs. We have checked the following:
–We thought it was a motor bearing, so we detached pump from motor, no noise heard.… Read more