Insane Hydraulics

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When Not Enough Power in a Hydraulic System is... Simply Not Enough Power

The most common complaint I hear equipment owners and users make about their hydraulic systems can be distilled into the following phrase: "my (insert machine's name) is slow (alternatively - doesn't have enough power)". If you have worked in a hydraulic shop for more than a day, I'm sure you'll agree.

The logic behind the statement is sincere - since the power produced by the engine is transmitted by means of hydraulics, it is, therefore, the hydraulic system's fault that the (insert machine's name again) is running slow.

If I were to classify such "not enough force" predicaments, I'd divide them into three groups:

The first case is simple to solve - the client needs a bigger machine (or a good therapist).

The second case falls directly into our laps, as we indeed are the right doctors for the case, with all our sophisticated testing equipment and unique expertise.

The third case is the tricky one, though, because when the poor hydraulic system is unfairly blamed for somebody else's poor performance (I am looking your way, diesel engine) things quickly become "complicated", when a hydraulics technician is called to solve such a "hydraulic problem", and spends half of his time re-checking the adjustments of a well-adjusted circuit, and the other half doing his best to prove to the client that the lack of power is nothing else but a lack of power.

The truth is - machines break and malfunction all the time, and prime movers aren't an exception. Sometimes the failures are "subtle", and may indeed require expensive volumetric testing of the hydraulic components to "put numbers" on things and define how big a part of the expected performance "is missing", but I have also witnessed countless situations when the prime mover's problem was so simple and perfectly detectable, that it seemed incredibly unbelievable that people not only would blame the hydraulic system but also pay for a costly assistance call to troubleshoot a loose fuel line or a clogged filter. And I am not talking about one or two isolated cases, I am talking about repeated situations I come across monthly!

Take a look at the video below. After a two-hour drive, and another hour spent re-checking the already well-adjusted system that "didn't have enough force...", it turned out that the beautiful inline six-cylinder 150 bhp air-cooled (!) diesel was starving for air due to the completely clogged air filter. In fact, the filter was so clogged, that the air intake tube was collapsing! By the way, before making the video, I asked the operator to start the machine and then to accelerate the engine, to better catch the collapsing tube - by chance the machine was left in "reverse drive", and when the fellow hit the throttle the machine charged in my direction - hence the shaky images as I jump away. Please, don't do what I did! And, please, forgive the old Nokia's video quality - the video is ten years old, the resolution is ridiculous but the idea is valid!

My point is - there's no shame in calling in a specialist whenever you feel that diagnostics of a certain failure is beyond your expertise, but there's a good amount of shame in calling in an expensive technician just to point at a clogged filter or a disconnected wire, or any other simple and basic thing you should've thought of yourself!

The best practice in any troubleshooting process is checking simple things (even when they aren't the most probable cause of the malfunction) before checking complicated things. Why? Because they are simple, and therefore easily and promptly doable. If you are an equipment owner - it saves you money, if you are a "troubleshooter" - it saves you time!

So yes, sometimes "not enough power" is simply not enough power.