A manufacturing company recently hired me to check the performance of four hydraulic pumps operating a large hydraulic press. The hydraulic pumps had clocked over 10,000 hours in service and the customer’s concern was that if pump performance was down, production would be too.

My test results revealed that the performance of all four pumps was within acceptable limits. So … Read more

In my previous articles on hydrostatic transmissions, I described the technique for determining the condition of a hydrostatic transmission using case drain flow, and discussed the role and influence of a flushing valve when doing this.

In response to these articles, some members were still confused about the influence of the charge pump when determining case drain leakage from … Read more

Despite his mother’s horror and protestations, my 18 year old son recently bought a motorcycle. It’s a Japanese, hog style machine. Ben would quite like a H.D. but that’s WAY out of his price range. The bike he got is 13 years old with 15,000 km (9,300 miles) on the dial. So he didn’t pay a lot for it. In … Read more