Trouble shooting

[AKKAMAAN]

A Trouble Shooting Story

Background

This was about a forwarder, a logging machine, and its operator, in the beginning of 1980.
A forwarder has a loading crane and a bunk to carry the logs.

http://www.youtube.com/watch?v=1DV1Vndlyco

All sorts a safety features started to be implemented in logging machines and other heavy equipment, like electric interlocks, so unintentional bad things would not happen. Like starting the engine when machine is in gear.
To operate the crane on a forwarder, operator use electric joy sticks, that are mounted on the arm rests. Crane cannot be operated when driver seat is turned forward (normal travel direction). There is a sensor that detects the position of the driver seat.

Story.
One morning the operator of a forwarder called the local Timberjack service center and reported that the engine did not crank. Battery was charged and travel direction selector was in neutral, brakes where applied etc, so the service center dispatched a technician to this logging site.
After arriving to the forwarder, the technician entered the cab, sat down in the driver seat and tried to crank the engine...engine totally dead....then tried to he turn the seat around, into the crane operating position, but the operators lunch box was in the way. After throwing the lunch box out, he tried to start the engine again...AND IT STARTED?Voila!!
There is a little 5 pedal on the floor, a direction selector, for travel when operating the crane. The lunch box was activating this pedal, and the interlock system prevented engine from starting.

Conclusion
Make sure you know how your piece of equipment is supposed to work, before you decide something is wrong. It is very common trouble shooting goes wrong due to lack of operator training and education. The owners manual, usually have enough information tell driver/operator what performance to expect from a car, log splitter, tractor, FEL, harvester, or forwarder etc. Manufacturer training class is one of the most important accessories in a purchase of any piece of equipment.

 

[mmurphy]

Probably about the best advice a guy can give. We directed a guy to do his own oil change in his truck. Now this guy was in his mid 40's at the time, so we never thought anything about it untill he kept coming back for more and more oil. He was waiting for the oil to get to the top of the motor. Sounds crazy but, we assumed he knew. Turns out he never ever even checked his own oil not alone changed it, always was done at some ones service shop. So my point is also we assume when people ask anything we may really not have a clue what they are really meaning, and yes the operators do need to take time to learn the operation of the machine.

 

[RedDirt]

Next best rule for troubleshooting is to only "fix" one item at a time. If you make multiple fixes or adjustments before re-testing you may never know what was really wrong or what fixed the problem.

I normally start with the first most obvious test or fix. If that does not correct the fault I proceed to the next. This saves a lot of unnecessary work and often saves unnecessary cost for parts the are still functioning fine.

 

[AKKAMAAN]

Next best rule for troubleshooting is to only "fix" one item at a time. If you make multiple fixes or adjustments before re-testing you may never know what was really wrong or what fixed the problem.

I normally start with the first most obvious test or fix. If that does not correct the fault I proceed to the next. This saves a lot of unnecessary work and often saves unnecessary cost for parts the are still functioning fine.

Very good comment RedDirt!! Try to take notes what steps you have taken, so you can track back your "fixes"..

Electric systems are usually more complex than hydraulic systems, but trouble shooting them follow the same rules.

When something needs a "brain" to trouble shoot, it is a good idea to take a brake, sit down with a cup of coffee and your "book", paper and a pen....

Before .you start looking for whats wrong, it can help to check what is working....that can prevent a replacement of a good component (pump, PRV etc)...

I try to ask my self "digital questions", questions that only can be answered with YES or NO....that will guide you better trough the process...

Taking notes is good, because it helps you to see all the "cards in play" at the same time......and do not forget to write down under what conditions you got that YES or NO answer....

Example:

There is a difference between these two questions...
A. Is there pressure in the hose?
B. Is there at least 1500psi pressure in the hose?

If we answer YES on question A, it might put us on the wrong track, compared to a NO on question B.

 

[AKKAMAAN]

Probably about the best advice a guy can give. We directed a guy to do his own oil change in his truck. Now this guy was in his mid 40's at the time, so we never thought anything about it untill he kept coming back for more and more oil. He was waiting for the oil to get to the top of the motor. Sounds crazy but, we assumed he knew. Turns out he never ever even checked his own oil not alone changed it, always was done at some ones service shop. So my point is also we assume when people ask anything we may really not have a clue what they are really meaning, and yes the operators do need to take time to learn the operation of the machine.

Another very good comment mmurphy!!

Communication skill is crucial in trouble shooting. Both parts that inter acts needs to know the proper "language"....

I see here on the forum that there are so many names, slang and abbreviations on the same thing, and there is a big risk for misinterpretation.....I am still trying to learn many new terms in English....

 

[wdchyd]

Good story Akkamaan,

sometimes troubleshooting needs all your senses....what do you see,hear,smell,feel.....well maybe not tasting it thou :confused2:

Probably the best for myself was learning hydraulic schematics years ago....at least you can learn how a circuit works before tearing into something....after all, how can you fix something if you don't understand how it works!!!!!

 

[relaqbr]

A Trouble Shooting Story

Background

This was about a forwarder, a logging machine, and its operator, in the beginning of 1980.

Hahaha. Excellent. My dad had 2 identical cars back in the seventy's when one would break down i would do my best to figure out what was wrong and then take parts from the other and see if it would run before i went and spent money at the auto parts store.

Bob

 

[Duff]

The 1st part of troubleshooting is know your machine, and this should happen the day you receive the machine, before any faults.
Get to know it, find out where everything is on it.

Follow the oil path around the machine: Oil comes from the tank, to the pump passes a main pressure relief valve, through a HP filter ( not always ), to the main control valve, through some QD's,from there to the hyd cylinder, from the hyd cylinder back to the main control valve, through a return filter and then back to tank.

And to know it more:
Put a pressure guage on it and record the pressure
Do cycle times of how fast it takes to lift the bucket from the ground, all the way to the top. and record. Do this for each hyd function.
Stick the recorded info on the beer fridge in the shed so you wont loose it.

Now when you do actually have a fault. Check the very most easist and simple things 1st, with out even laying a spanner on the machine.
Check the oil level, check there is not a puddle of oil on the ground, check all QD's are properly connected. check that the impliment levers are not obstructed, check that all safety interlocks are being pushed, check that no mechanical safety devices are on etc etc.
If the machine has been worked on, and the fault started after, then go back to where it was worked on, and check !!!! ( hoses on wrong way etc. )

None of the above has costed you a cent ( except for maybe a hyd guage ), however you will solve many problems with the simple checks.

You still have a fault after simple checks.
Now get the facts on whats happening.
You now need to work your machine and find out if the problems is isolated to one impliment or all of them.
Is it making a noise? Is it slow in one implement or all of them?
Do your cycle times of each impliment or just the affected one and compare with results on the beer fridge ( same as pressure checking with hyd guage)
Read the machine manual, and make sure you have a good understanding on how it all should work.

Still no money has been spent or machine pulled apart.

Now with your knowledge of the machine and your hard facts come up with a stratagy to fault find the problem.
Give yourself a process of elemination and try to check the easist and cheapist things 1st, before you start forking out the big dollers on pumps etc.

Solve the problem and fix !!

Once done, get a beer out of the fridge and pat yourself on the back !

Duff

 

[AKKAMAAN]

The 1st part of troubleshooting is know your machine, and this should happen the day you receive the machine, before any faults.
Get to know it, find out where everything is on it.....


........ get a beer out of the fridge and pat yourself on the back !

Duff

Good post Duff!!:thumbsup:
I agree with everything, except about the beer.....some times it takes "a beer" before getting started with prouble shooting.....a so called "tranquilizer"....

Personally I prefer a cup of coffee!!

 

[mmurphy]

Personally I prefer a cup of coffee!![/QUOTE]

And a diet Pepsi!!