I attended the Fluid Power Conference & Expo in Milwaukee last week. One of the seminars I attended was the Trouble Shooting Hydraulic Systems by Jim Casamassa from Oilgear. The presentation was on a simple approach solving complex problems with Hydraulic Systems.

What is needed to solve these problems?
Calibrated Gauges, Infrared Thermometer, Quick Disconnect Test Ports, Accurate Hydraulic Circuit Diagrams, Machine Cycle Explanation and Machine Operator.

What are the Most Common Problems?
Noise, Heat, Low Pressure, Low Flow, Instability

What steps are needed to solve these Problems?
Don't assume Anything
Consider the Source
Start with the Obvious
Isolate components
Ask a lot of Questions
Take One step at a time
Change One thing at time

Do you use this approach to solve your problems?

Glenn;
In my area, the MidWest, I find there are very few Mechanics or Mechanical Engiineers who have enough knowledge of Fluid Power Equipment to read a Schematic, if they can find one. They also have little if any knowledge of how the hardware is made and how it should functio even if they could read a Symbol on a Schematic.

On top of that the Schematic is probably out of date since the circuit was modified to get it to perform satisfactorily or was changed over the years to upgrade it or make it do something different from the original intent. Needless to say, the schematic was not updated during any of the aforementioned modifications so when this person with no training or experience in Fluid Power finally finds the schematic they do'nt understnd they are still in the dark.

Since there are very, very, very, very few persons in the Industrial World that have more than a rudimentary knowledge of Hydraulic and Pneumatic systems or circuits there is a big problem when a machine breaks down.

Now, If it happens to be an Electrical problem it will be quickly diagnosed by a trained Electrical Engineer or Maintenance person who has had a lot of triaining in the Electrical field. In fact, many Hydraulic or Pneumatic problems are solved by an Electrical type who can read the Electrical schematic and can determine the Solenoid on a Directional Control Valve has an input but the actuator it is controlling is not moving.

Most companies, Small and Large, handle the lack of on site Fluid Power knowledge by calling the Salesman that sold them the equipment. The salesman is usually the one who designed the circuit, drew the schematic and assisted the maintenance persons or machine builder on how to hook the equipment up. This scenario works most of the time since the salesman wants more business and is very helpful if a problem is found with their circuit or components.

I have taught many Hydraulic Trouble Shooting classes and found early on that the greatest hurdle in such an endeavor was the student had a schematic they could'nt read since all the symbols were meaningless. Even the few who had some knowledge of symbols usually had very little understanding of how the component the symbol represented was supposed to perform. That was even more of a problem when the component was used in a unique way by some expert, or non-expert circuit designer.

Since those early classes I have put together an Industrial Hydraulic Trouble Shooting book that I used to teach Mechanical and Electrical Maintenance Apprentices at a local plant. It is offered after a Basic Fluid Power course is completed. Over half of the 64 Hour class is on how the Pumps, Valves and Accessory items are made and how they normally perform in a circuit. All the book shows Cutaway drawings of the components and the ISO Symbol that represnts that part on a schematic.

Following that is a section on trouble shooting specific components by going through the ways each item can fail and explaining how they act during specific failure modes.

The next section is practice on identifying components that match a symbol on some simple schematics.

After that is a section with non working schematics that have missing or mis-applied components or features such as mis-applied Flow Lines. There is an explanation of how the circuit is supposed to work followed by an explanation of how it has failed. The students must determine what the problem is and what to do to get the circuit operating as designed.

The folling section has several schematics of multi-function working circuits with questions on what specific components do or what problem they might cause when they fail or are not setup correctly.

Folllowing that is a section for classes of persons from multiple companies with schematics of working circuits that have a list of symptons that the student must find the component/s that are causing that malfunction. This section uses actual company schematics when the class is held at a company site.

The final section is a set of symbols that have a Generic Cutaway along side to give a picture of the component that symbol represents.

As with all Fluid Power training, if you leave the class all fired up and then work on everything but Fluid Power circuits for 6 months all the information from any class is hard to dredge up. That is why I believe there should be dedicated Fluid Power persons or at least one person in small plants that are trained in Fluid Power and handle all the problems that arise with hydraulic and pneumatic powered equipment.

Oh well, Someday, Maybe????????

Trouble Shooting is a Talent . It is correct for Doctors and
also for Fluid Power Specialists. The key points are the know how to:
1) Read.
2) Listen.
3) Watch.
Now (Read+Listen+Watch)Leads to ---> Diagnosis.
At this stage you can start trouble shooting.