July 10, 2007 

'Inside Hydraulics' Newsletter

1. Get the hydraulics knowledge you need NOW - and take care of it later
2. Cart before the horse? What do you think?
3. Anatomy of a hydraulic oil failure
4. Content for your web site or e-zine
5. Help us spread the word
6. Tell us what you think


Get the hydraulics knowledge you need NOW - and take care of it later

Quite a few members have written to me over recent months to say they would love to advance their hydraulics knowledge with the Fluid Power Mother Lode, but would prefer some sort of lay away option.

So in response to this feedback, a new, equalizer ownership plan over six months is now available.

We're doing this as a test and may or may not continue it, depending on the results. So if you'd like to take advantage of this easy ownership option, point your browser to http://www.hydraulicsupermarket.com/motherlode.html and get your 'Mother Lode' today.

The Nice Things People Say

"I am the lead engineer conducting Reliability Centered Maintenance for the U.S. Air Force on several platforms. Your book Insider Secrets to Hydraulics has been a gold mine of ideas ..."

Lynnwood Yates, CMRP
Senior Reliability Engineer
Wyle Laboratories, Inc

2.   Cart before the horse? What do you think?

In Issue #63, I wrote about the advantages of defining your maintenance and reliability objectives for a piece of hydraulic equipment before you even order it. In response to this article, I received the following from one of our members:

"As an engineer for a heavy equipment manufacturer, I have to take exception with your advice in the last newsletter. I believe selecting a hydraulic fluid, and then requesting the equipment manufacturer to design around that is putting the cart before the horse.

It makes much more sense for the equipment manufacturer to design the system for temperature, life, component availability, cost, and the million other things that go into machine design.

Would you tell Ford that you have a set of brake pads, and would like a car designed that could use them? No, you rely on the manufacturer to provide a system, and take their recommendation."

Hmmm... looks like I'm in trouble - again. I feel a bit like David, being pounded by Goliath. This member didn't reveal which OEM he works for... but the mind boggles with possibilities.

Needless to say, I don't agree with my colleague's assertion that the reliability-based strategy I advocated in last month's newsletter is "putting the cart before the horse". Let me explain with an example:

Say I am about to acquire a 25 ton hydraulic excavator. And let's say for example, this machine is fitted with Rexroth pumps and motors.

According to the pump manufacturer, optimum performance and service life will be achieved by maintaining oil viscosity in the range of 25 to 36 centistokes. I also know that in my location I expect to use a VG68 weight hydraulic oil and the brand of oil I use has a viscosity index of 95.

This being the case, Rexroth are telling me - indirectly of course, that if my new machine runs any hotter than 70 Celsius the performance and reliability of their pumps and motors will be less than ideal. Not only that, with 70 Celsius as the maximum operating temperature, the oil will last longer, the seals will last longer, the hoses will last longer and almost every lubricated component in the hydraulic system will last longer.

So being the sophisticated buyer that I am, I say to the OEM - before I order the machine: "I expect ambient temperatures at my location as high as 45 Celsius and under normal conditions (no abnormal heat load in the system) I want this machine to run no hotter than 70 Celsius. If you deliver it to site and it runs at 85 Celsius (or whatever) on a 45 Celsius day, then you'll have a problem on your hands."

I'm not suggesting this is in the interests of the OEM - clearly it's not. It's going to make their life more complicated and cut into their after sale revenue. No, it's totally in the interests of the guy signing the checks to keep the machine running. Luckily for all the OEM's out there, very few machine buyers will approach a new equipment acquisition with this level of sophistication.

I'd like to hear from some hydraulic equipment end-users on this issue. Would you "lay down the law" to an OEM when purchasing a machine - in order to get the reliability outcomes you desire? Or are you happy to rely on the OEM and take delivery of a one-size-fits-all machine and live with any reliability shortcomings it may have?

Wasn't it Henry Ford, the father of mass production, who said about the T Model Ford, "You can have any color you like - as long it's black"?

"This book has the potential to save many organizations lots of m0ney. It should be on the bookshelf of every engineer, supervisor, planner and technician that deals with hydraulic equipment... it's worth its weight in gold." Find out more

Alexander (Sandy) Dunn
Plant Maintenance Resource Center

3.   Anatomy of a hydraulic oil failure

For an eye-opening case study on a hydraulic oil failure, read Brendan Casey's article in the May-June 2007 Issue of Machinery Lubrication magazine, available here. To receive a complimentary subscription to this informative magazine (US and Canada only) go to: http://www.machinerylubrication.com/hydraulic1.asp

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 editor@hydraulicsupermarket.com 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 17 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: http://www.InsiderSecretsToHydraulics.com

5. Help us spread the word

If you've found our 'Inside Hydraulics' newsletter interesting and informative, then chances are you have a colleague who would too. Help spread the word about 'Inside Hydraulics' by forwarding this issue to a colleague. If they share your interest in hydraulics, then they will surely appreciate being told about this newsletter.

New subscribers can get the newsletter by completing the form at http://www.insidersecretstohydraulics.com

6. Tell us what you think

We would love to hear what you think of this issue of our 'Inside Hydraulics' newsletter. And of course, if you have any suggestions for future issues, please send us those too.

Just e-mail the editor at: newslettersuggestions@hydraulicsupermarket.com

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