What do you think is the most valuable thing in the arsenal of tools of a hydraulic technician? A pressure gauge? A flow meter? A multimeter? Well... I couldn't agree more that these are all great tools, but in my opinion, the most valuable tool is a pen. Maybe a pencil. And, believe it or not, I learned how to use one a long time after I learned how to work with pressure gauges, flow meters, and other pieces of "very hydraulic" diagnostic equipment.
Let me explain why I believe the pen is the best friend of a technician. That is so because techs are humans, and most humans can't rely on their heads for quickly storing and then randomly accessing multiple bits of information. And this is exactly what you need to do when you troubleshoot or adjust a more or less advanced hydraulic system. Our brains suck at quickly remembering more than a couple of things at a time! You read a pressure, then you read a second pressure and note an abnormal relationship between the two, then you read the pressure in the first point again, higher this time, and once again note a different abnormal pattern in regards to the second one and then... wait... how high was it when you measured it the first time?!! Damn it! Already forgot! You see where I am coming from, right?
This is why I advise using a pen and a notebook for registering literally everything when you work with hydraulics. All the pressures that you read, all the settings that you make - absolutely everything should be written down.
The way that you put things down doesn't matter, as long as you can retrace your steps and key readings in order to register a complex behavior of a system and thus be able to review it at will (and then come up with a solid troubleshooting theory).
Very often it may be necessary to see how a system responds to a setting change, and then this very setting needs to be set back the way it was before. Believe it or not, it is possible for a tech to turn an adjusting screw and then not be able to recall how many turns he made literally seconds ago! This is not crazy, this is normal human function. When your attention is spread over a slew of things - a pressure gauge, a system noise, an actuator's speed or position, etc... and you are receiving multiple inputs at once - your brain can only process that much, and this is why putting everything down on paper is so helpful! Literally - writing something like "turn CW two turns" can seem miraculous when you've turned the setting screw, then did a couple of other things, and then got back to the setting only to wonder how many turns you just made - at which point you look at your notes and go - "Oh yes! Two turns!"
I, personally, like to make tables of measurable parameters. For example - most of the times I start with making a table of baseline readings, and then fill it in after the necessary adjustments (component replacements, etc...) are made - to see clearly what changed and what didn't. Even a relatively simple system can have multiple parameters that must be written down in order to assess its function - oil temperature, engine rpm, system pressure, pilot pressure... - everything must be put down on a piece of paper.
Sometimes I even go a step further, and after evaluating a system's diagram, I put down a small list of expected readings - before I make them. This can be very helpful.
But, once again, how I do it is not the point. The point is - the sooner you realize that your brain sucks at remembering random values that are thrown at it a handful at a time, and start using a pen and a piece of paper to register as much as possible - and I mean both the parameters of the system you are working on and the interventions that you are making, the sooner you will discover how extremely helpful this practice is!
Our brains should do what they do best - i.e. coming up with ideas - and the piece of paper in your hand should be taking care of storing and presenting whatever needs to be stored and presented. Make it a habit of yours to register a reading in writing whenever you take one - you will be thanking me soon enough.
I imagine that my millennial readers will say something like - "Writing things down on a piece of paper? Like, with your hands? Dude, ever heard of this thing called smartphone?"
Yes, I have, and I use them all the time, believe it or not, but in a "seriously industrial" environment nothing can beat the ruggedness of a hard notebook and a pencil. I can put my notes under an extended outrigger and they will be fine. Can you do the same with yours?
A funny story. I know for a fact that my brain can't remember anything for more than a couple of seconds, and so I write things down even when I am not troubleshooting hydraulic stuff. Like my ideas for the blog articles. When I have an idea - I need to write it down at that very moment, because if I don't - the only thing that remains in my head is the recollection that I've just had a great idea... only I can't remember what it was anymore!
So, when I saw a hydraulic tech running around an excavator, adjusting this and that at the speed of lighting, pressure gauges everywhere and all, and then failing to recall the readings from a couple of minutes ago when the engine was at idle - I thought about how easier it would be for him to be putting things down on paper, and then I thought - "great, I should write about this in my blog", and so I quickly scribbled five words on a piece of paper "pen is your best friend", and then put it on the top of my office desk so that I wouldn't forget about it.
The next morning, when I entered the office, I saw my wife holding the note in her hands. And when I saw what was written there - I also realized that yesterday, as I was hurriedly writing my valuable idea down, I kind of forgot to put a space between the "pen" and "is"...
Then my wife, as a person who is accustomed to finding my "wisdom notes" everywhere, said: "I understand that this is a note for you not to forget something. I only wonder if the first word is a verb or a noun..." Can't remember the last time we laughed that hard about something!