November 10, 2009 

'Inside Hydraulics' Newsletter

1. The winner is ...
2. My top 10 'Cardinal Sins', continued
3. How to synchronize hydraulic cylinders
4. Content for your web site or e-zine
5. Help us spread the word
6. Tell us what you think


The winner is ...

In the August issue of this ezine, I ran a little competition in which I invited readers to send me their favorite must-not-do or 'Cardinal Sin' related to hydraulics.

Several hundred members submitted entries and I've edited and compiled them all into one, succinct document, titled:

132 'Cardinal Sins' of Hydraulics ... What NOT To Do With Hydraulic Equipment.

As an incentive, and to make it a bit of fun, I announced that the 10 entries I judged to be the best would receive as a prize; a copy of my new children's picture story book: Farmer Mick Harvest Time Havoc (for those of you who are curious, you can check it out here).

Judging the winners was no easy task. Because as the final document shows, there were a LOT of good entries. But here are my top 10. Your favorites may differ and that's fine, but as is the norm in these things, the judge's decision is final and no correspondence will be entered into.

Oh, and perhaps not surprisingly, some of the more common 'sins' were sent in by more than one contestant. So if do you see something mentioned below that you sent in yourself, the guy in the winner's circle either got in first or said it better.

So with that in mind here are the winners, in no particular order:

The corporate award goes to Case New Holland (CNH). The guys at CNH must pay attention to their hydraulics because I received multiple entries from their various locations around the world. Truman Lomi who works for CNH, Sydney Australia scores for this one:

"Condemning a hydraulic component as faulty without proving it through a logical process of elimination."

If you employ people to work on hydraulic equipment and you do nothing else but drum this one into their head, you will save yourself a small fortune.

Truman's colleague at CNH Burr Ridge Illinois USA, Bruce Arndt, also makes the top ten with this no-no:

"Not ensuring all accumulators are completely discharged prior to commencing work on a system."

This should be obvious but isn't always to the uninitiated. A mechanical equivalent is trying to disassemble a spring-applied air brake without considering the potential energy of the compressed spring - which you can't see - you have to know it's there and take the necessary precautions.

Kudos to Kevin McCaffrey and his team at Excel Hydraulics, Sydney Australia. They did a brainstorming session around this and came up with many good submissions. But this 'sin' stood out for me:

"Measuring o-rings for replacement purposes (it's the grooves you should be measuring)."

This may seem harmless enough on the surface, but the upshot of it is it often results in the wrong seals being installed. And this can cause a lot of heartache.

continued below ...

The Nice Things People Say ...

"The knowledge I've gained from this information has been so valuable it has earned me a raise!" Find out more ...

Jack Bergstrom
Heavy Equipment Mechanic
Sharpe Equipment

2.   My top 10 'Cardinal Sins', continued

continued from above…

Sylvain Roy who works for Trican Well Service, Red Deer Canada, nailed this common mistake which gets a lot of inexperienced circuit designers into bother:

"Believing piloted operated check valves are motion control valves - and that counterbalance valves are load holding valves."

The best 'Cardinal Sins' cut to the quick. Like this one sent in by Sebastien Gagnon, from Equipements Anderson, Chesterville Canada:

"Allowing a hydraulic hose to twist when it's being tightened."

Stephen Brosnan, who works for the CSIRO in Brisbane Australia joins the winners list too with:

"Modifying the hydraulic (or electrical) circuit but not updating the schematics to reflect the changes."

There's nothing worse than trying to troubleshoot a complex hydraulic system with a drawing that's not accurate. And in the case of an electrical circuit, I remember once working with a battle weary electrician, troubleshooting a problem on an electro-hydraulic system, and as soon as he realized the drawing wasn't accurate he became very wary, stating: "That's how you get fried!"

Steve Cater of Freco Fluid Power, Nepean Canada makes the cut with:

"Replacing a component which has failed catastrophically without cleaning the tank and flushing the system."

Anybody who's worked in the hydraulic repair business knows anyone who commits this 'sin' causes a lot of weeping and gnashing of teeth.

Another 'Cardinal Sin' which really is the hallmark of a rank amateur, is this one submitted by Hendrik de Villiers from Bahrain:

"Applying silicone sealant to tank lids or o-rings."

And here's another trap for the uninformed, submitted by Michael Calverley who works for Baker Atlas in Algeria:

"Assuming the filter element is correct - just because it fits."

I committed this sin many years ago when young and inexperienced and only through sheer luck did I avoid a very expensive disaster. It's rather a long story which I'll save for my Hydraulics Pro Club members.

And finally, George Robertson from Fugro in Aberdeen Scotland summed up this whole exercise with:

"People who have been around hydraulics for years, who "know it all" making the same mistakes again and again, and not taking the time to really understand how hydraulics work."

When it comes to hydraulics, I don't think you ever know it all. There's always something to learn, AND there's always a deeper level of understanding to be had about the things you 'know'.

And if your name appears above, a special child on your Christmas (or other) gift list can be ticked off. Because of copy of Farmer Mick Harvest Time Havoc will be on its way to you shortly.

If you are one of the winners named above, please send me an email with the mailing address you'd like the book shipped to.

"This book has the potential to save many organizations lots of money. It should be on the bookshelf of every engineer, supervisor, planner and technician who deals with hydraulic equipment... it's worth its weight in gold." Find out more

Alexander (Sandy) Dunn
Plant Maintenance Resource Center

3.   How to synchronize hydraulic cylinders

The problem of synchronizing multiple hydraulic cylinders arises in many applications. This Instant Knowledge report introduces and explains eight different solutions to this problem. To assist you in selecting the most suitable solution for your application, each method is considered according to its level of accuracy, cost and complexity. The methods discussed are applicable to any number and any type of hydraulic actuator. Find out more

4. Content for your web site or e-zine

Need some fresh content for your web site or e-zine? You now have permission to reprint these 'Inside Hydraulics' articles on your web site or in your e-zine, provided:

1. Each article is printed in its full form with no changes.

2. You send an e-mail to to advise us where you'll be publishing them.

3. You include the following acknowledgement at the end of each article:
About the Author: Brendan Casey has more than 20 years experience in the maintenance, repair and overhaul of mobile and industrial hydraulic equipment. For more information on reducing the operating cost and increasing the uptime of your hydraulic equipment, visit his web site:

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