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My toolbox is no longer full of merely tools. Many of the items in my box are not tools, but rather instruments. In an age of diagnostics, people expect me to plug a little magic box into their car’s computer to tell me what part to replace on their car. We mechanics have our own little secret: it doesn’t work this way.
Some of the instruments we use are sensory: our five senses, and that immeasurable sixth sense. Diagnostic ability is a combination of reliable equipment, sensory abilities and good old experience.
When I was 10, my father introduced me to my first instrument, an antifreeze bulb with four differently colored balls in it. The coolant was drawn in and the color of the last ball to float indicated the temperature at which the water and antifreeze mixture would freeze. In southern Louisiana, if the freezing point was down to 20°F, it would cover anything we would see in my lifetime. That simple bulb is still used in most shops today.
What instrument was used before antifreeze bulbs? I asked my father, and he replied “we did it like the Russians.” He worked as an instrument technician on Boeing B-17s at Tinker Air Force Base in Oklahoma City during WWII. One of his friends was assigned to Russia to accompany some of the Bell P-39 aircraft they bought. The P-39 used a liquid-cooled GM Allison V-1710 engine and required ethylene glycol as a coolant and antifreeze. In the haste of war, the friend learned from the Russians how to test for antifreeze when they’d lost or broken their hydrometers. They tasted it!
Do not try this yourself! Do NOT taste your car’s antifreeze. Take my word and those of my fellow comrades: new antifreeze is sweet and its sweetness dissipates as it ages. With some time, a skill can be developed for testing antifreeze potency. Many glycols are sweet and are therefore used as a food preservative.
Used in small quantities, glycols are safe and increase the shelf life of baked goods. My children nearly fainted when I showed them they were eating antifreeze donuts. Plainly listed in the ingredients of those little powdered donuts is glycol.
I use my senses daily in my on-the-job diagnostic procedures. We can often diagnose a single car by the sound it’s making as it cruises by the shop. The smells a car makes can tell a mechanic many things, along with the other senses of taste, sight and touch.
In this magazine are advertisements for instruments, diagnostic services and equipment. However, we must learn to incorporate our senses to get the best results. When my customers see me plug my diagnostic computer to their car, they want to see how it tells me what to fix. I tell this story to illustrate how not only this instrument but also my senses, experience and other instruments all work together.
I ask the customer to imagine he owns a small hotel, with 10 floors and 10 rooms on each floor. As he sits at the desk one night, a fire alarm goes off. I explain that my computer will tell what floor the fire is on. It will tell one of three rooms involved and it will suggest tests for each of the rooms.
We have now reduced the investigative workload from 100 rooms to three rooms. These tests come from experience and repair manuals. For instance, touch one door handle to see if it is hot. See if another door is leaking smoke. Smell another of the three doors to determine what sort of fire it is. According to the result, each door determines the next step: whether we’re to use another instrument or get the tools to fix it.
This example shows how a combination of instruments, literature, sensory information and tools are required to solve the problem. In his recent column, ML editor and publisher Jim Fitch called for a more professional job description for lubrication managers.1 In his proposed job description, he used verbs such as “ensure, establish, select, identify and oversee.”
Reading this proposal of standards and his request for feedback, I saw that all the utilities I use in my business are in use here. Reference materials, instrumentation data, experience, feedback, and lots of sensory usage were the call to action set forth in his proposal.
I had a cousin, Vernon, who was promoted to maintenance foreman at a gas compressor station. He was assigned the nastiest, most poorly kept station on the line. The first time I saw the plant it had dirty work areas, leaking flanges and general disrepair throughout the plant. The following year, the plant floor was clean and painted, and work areas were organized and well-supplied with tools and safety devices.
Despite the newly painted floor, there were still leaking flanges everywhere, and under each leaking connection was a rag to collect the drip. Vernon was the sort of guy who always had the cleanest car in town. He would never drive his Corvette in the rain, as it might get mud on the undercarriage. But what looked like a joke, dirty rags on a beautifully painted floor, my cousin saw as establishing priorities.
When asked why he hadn’t fixed all the leaks, he replied “I cannot do everything in one year, and the rags tell me what one to do next.” He had developed a system to determine which leaks to fix first using rags, counting and his experience. At the end of two years, his plant had the least (an improvement from having the most) downtime, lower off-stream times and lowest unscheduled maintenance.
This is what Jim Fitch called for in his column. Vernon used data from the jobsite, professional experience, a plan of execution designed from instrument data and observation. All of these resulted in lower operating costs and Vernon’s promotion to station manager.
Vernon’s simple procedure was the rag count, definitely not a high-tech instrument, but an accurate one. I wonder if Vernon smelled out problems.
Experienced automotive mechanics have developed their sensory skills. I use mine on-the-job every day.
The noises an automobile makes can reveal many tips to solving the problem: where to start looking, how serious the problem is and sometimes exactly what is wrong. It may seem hard for the general public and the lay mechanic to believe this, but it is true: Certain clicks, knocks, rattles and whines can bring up powerful remembrances of past challenges and their solutions.
In one of my prior columns entitled “Almost Burned” (Machinery Lubrication, September 2002), I referred to the burned transmission fluid. I knew it was burned because it both smelled and looked burned. I have a great recollection of the smells of a burned bearing, motor oil, belts and alternators.
There is difference in the smells of motor oil, transmission fluid, brake fluid, coolant, and heavier lubrication oils and greases. They smell different - burned or not.
If a customer complains of no power, low gas mileage and a strange smell emanating from his vehicle, the first thing I do is touch each wheel and smell it at the same time. I am looking for a sticking brake.
If a customer claims his tailpipe is smoking, I ask what color? Different colors of smoke define different failures. Examples include:
Water/blown gasket or cracked heads, usually serious trouble
Oil/ burned pistons, or cylinder head leakage
Engine running too rich, computer or injector trouble
White smoke on diesel
Running rich, same as black on gas engine
Black smoke on diesel
Normal function, usually no problem
Long before we had sophisticated instruments to determine the source of car trouble, we relied upon what was given to us. Our senses remain an important part of our diagnostic tools today.
Fitch, Jim. “Wanted: Lubrication Management Professionals.” Machinery Lubrication magazine. November 2002.