Hydraulics Pro Club member Rich Catalo sent me this tragic story:
"We deal with a very large dock and dredge company. They have many pieces of hydraulic equipment from different manufacturers. The last call I received was due to a tech who removed a hydraulic cylinder that was in need of a reseal. The tech did OK removing the cylinder but failed to cap off the hydraulic hoses with proper plugs. He stuffed shop towels in the hose ends instead. The cylinder was reinstalled and the hydraulic hoses reconnected. But the tech forgot about the shop towels and ran the system. The rags eventually got caught in the control valve."
This reminds me of a similar incident which occurred many years ago. Fitters on a mine-site changing out a main pump on an O&K/Terex RH200. Big pump. 1000 L/min at up to 350 bar. And, at the time, worth about $40,000.
You can imagine: dirty mine-site, excavator covered in dust, and a 6-inch diameter inlet hose open to the elements. So one of the fitters stuffs a rag into the pump's inlet hose to keep the dirt out.
Well, you can guess what happened. Rag left in inlet hose. Pump started up. Five minutes later THAT pump is being changed out. With entry into the Guinness Book of Records for the shortest pump-life in history.
The obvious lesson here is NEVER stuff anything into a hydraulic hose, tube or pipe. Because if it's not stuffed in, you can't forget to take it out.
But there's a wider issue to consider here. Were the techs involved in these situations stupid or just human?
I say it's the latter. In the heat of battle they forgot to do (or un-do) something critical. And to forget doesn't make you stupid. It makes you human. It's akin to a surgical team leaving a sponge or clamp inside a patient's abdominal cavity.
It shouldn't happen. But it does.
In the techs' case, they were trying to do the right thing: prevent contaminant ingression. Albeit in the wrong way. And absent a written checklist to prompt them to remove the inserted rags, well, they were a bug looking for a windscreen.
For a long time now I've advocated the use of checklists. Especially when starting or restarting a hydraulic system. And the start-up procedure I outline on pages 106 to 108 of The Hydraulic Maintenance Handbook has 26 steps. Each of these steps is there to prevent a potential component-killing incident like the ones described above.
And this makes The Hydraulic Maintenance Handbook very cheap insurance. It is true that you can't fix stupid. But you can and should take ACTION to ensure a memory lapse during your next hydraulic component change-out doesn't win you
the dubious title of causing the shortest component service life on record.
Bottom line: not using a checklist when commissioning or re-commissioning a hydraulic system can be a costly mistake. And to discover six other costly mistakes you want to be sure to avoid with your hydraulic equipment, get "Six Costly Mistakes Most Hydraulics Users Make... And How You Can Avoid Them!" available for FREE download here.