Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/1123345
20 | May - June 2019 | www . machinerylubrication.com As a hydraulic instructor and consultant, I have met thousands of people whose job consists, at least in part, of the maintenance and repair of hydraulic systems. e number of hydraulic troubleshooters I have come across, however, I can count on the fi ngers of one hand. For the most part, I have encountered a lot of excellent hydraulic parts changers. ese are people who have worked on and around hydraulic systems for so long that they know changing a specifi c part typically corrects a certain problem. ey may or may not know exactly why this is, but they know from experience that replacing this part fi xes the problem. Now I don't mean this in a derogatory way. Someone with that level of experience is valuable, but it isn't troubleshooting; it's parts changing. It works fi ne whenever changing a part does in fact correct the issue. e trouble comes when a parts changer changes a part and it doesn't fi x the problem. What do you suppose the parts changer's next course of action may be? If you said "change something else," you would be correct. Frequently, the parts changing process continues until one of two things occurs: either the machine is repaired, and everyone rejoices, or the system is put into such a state that someone must be called. Quite often, that someone is me. While it is possible to repair the system this way, it is also possible to add a problem or two whenever a compo- nent is replaced that was not bad. Usually, by the time I am called to help, a considerable amount of parts changing has occurred, and what began as something simple may have progressed into multiple issues which can be very time consuming to diagnose. Pressure or Flow? If I had to pick a single concept that keeps most parts changers from becoming troubleshooters, it would be the failure to understand the Pressure vs. Flow: Understanding the Difference HYDRAULICS Jack Weeks | GPM Hydraulic Consulting "A pressure problem in a hydraulic system is rarely the pump. It is almost always another bad component in the system." In this schematic, a fi xed-displacement hydraulic pump is represented by a circle, with a fi lled-in arrowhead indicating liquid output.