Tech

[mekanik]

Last week we got a call from a local trucking company. They had an air problem with a 2016 Pete. The shop the normally use could not get them in for a while. They desperately needed the truck fixed. The shop they normally use troubleshot the problem as being caused by the air dryer and gave the driver a Bendix ADIS dryer. The dryer was cycling every few seconds. The shop foreman asked "Do you want us to troubleshoot it first?" Owner said "No the tech at the other shop did already". He said the door' is open drive it into the shop and we will get to it right away.
I drained the air and slid under it and replaced the dryer. Once done I ran the engine and cycled the compressor a few times and it worked as should. I released the park brake to back out of the shop and I could hear air blasting from the rear of the truck. A major air leak. A air line to one of the brake chambers had rubbed through in a suspension bolt. I replaced the line and sent him on his way.
I can't believe the driver did not know he had an air leak and I can't believe the "Tech" did not diagnose the leak.

 

[DMiller]

Supposed to Chock wheels, shut down engine, Release Parking brakes and test for air leakage on Brake application on Pre Trip.. At least I Did/Do.

 

[Birken Vogt]

When I think "mechanic", I think Gomer Pyle who knows how to perfectly turn screws on a carburetor or what type button and adjustments to make on a NTC.

When I think "tech", I think using a DMM to troubleshoot CAN bus and observing whether it has a relatively constant voltage (data flood) or pulsing or lower voltage (correct packets) and knowing how that works and what it means.

I think to be competent to serve your customers, you need to be both at the same time.

 

[Truck Shop]

CAN Bus Explained - A Simple Intro [2023]

What is CAN bus? How to log CAN bus data? Where does J1939, OBD2, CANopen fit in? See our CAN protocol intro tutorial for the Controller Area Network basics!

www.csselectronics.com

 

[thepumpguysc]

Birken:: #19 button and a PURPLE spring..lol

 

[DMiller]

I will agree there are options within CANBUS that cannot happen on Hard Wire systems, yet WHY do they place lighting functions IE T/S, Stop lamps thru CB systems? SIMPLE is rather conspicuously missing here. 2012 HD Motorcycle, four wires from lighting circuit, three breakers/fuses, 2016 HD Same platform, SEVEN Fuses/breakers, ECM just for T/S/Stop lamps fed down three wires. HOW in the hell is that "Simpler"?

 

[Truck Shop]

HOW in the hell is that "Simpler"?

It's not--Over designed not necessary. A DT12 that had issues CANBUS was not communicating.
Now when the Detroit Transmission Troubleshooter spends 2.5 days onsite and cannot figure out
why it's not communicating Houston has a issue. That tractor was down for 7 weeks total time.
End result was everything was changed out including the transmission which every piece was
sent back to DT. Never did hear the reason.

 

[DMiller]

Buddy of mine and I picked up our N-Line trailers same time, rode up together to have hitches installed(Free Labor) and wiring added. My own was a Plug and Play "T" in system for tail and ID lamps and two turn signals(Free), his was a Massive $197 module and a significant small harness, for $39. Mine a 2012, his that 2016 I noted above. JUST to run Trailer lamps. BOTH were Road Glides. His has been replaced once and may be needing again.

 

[JD955SC]

At least half of the dumb stuff I see is Engineers screwing with stuff to justify their jobs and show how smart they are. Even better for them if they can not only make it more complex but also more fragile then they can engineer the “solution” down the road and be the “hero” for what they screwed up.

And god forbid you contact the OEM for help on something complex that you can’t figure out because they often don’t know their own systems.

All I want is decently engineered systems and well written support literature that is easy to follow and understand so I can learn, understand, and fix what I work on but apparently that is too far of a bridge.

 

[92U 3406]

And god forbid you contact the OEM for help on something complex that you can’t figure out because they often don’t know their own systems.

"Have you updated the software to version xxxxxxx?"

I swear that's the equivillent of calling the IT department and they tell you to turn the device on and off again. 99% of the time it does nothing.

 

[oarwhat]

A bit off track but same issue. Bought a new tube heater to replace old for less issues. Heater won't work. PC led shows no issues. Call tech and figure out it's the gas valve. I cut the old one open and it had a freaking computer chip in it. WHY?? It's just a coil to open the valve. New valve I bought was old style.

 

[Truck Shop]

I guess I'm a Gomer Pyle. Here's what this Gomer dealt with years ago.

The start of component communication started in the 50's called the Electrojector, a design built
by Bendix. Bendix sold the idea to Robert Bosch which refined it and named their redesign
Jetronic, first installed in production VW cars in 1967. In the early 70's it was renamed D-Jetronic.

Bosch Jetronic is where everything on the market today spawned from. At the time {not until
mid to late 70's was any type of trouble shooting tool invented. It like all other things at the time
were analog. There were no codes only a the procedure of measuring ohms and voltage.
It had to be damn near perfect readings to operate correctly. Injectors used just slightly less than
volt to operate. Now the system wasn't terribly complicated but just enough so the slightest variance
in voltage caused major issues. The control box was not called a ECM or microprocessor but instead
a Modulator with about 20 plus resistors inside, there was a map sensor and fuel pressure sensor.
It operated on fuel pressure, with a cold start injector the precursor to what's common rail now.

Troubleshooting was extremely time consuming. There were no weather pack connections, no sealed
terminal ends, ground connections had to be spotless. The insulation on wire harness was the product
of the period. Prone to cracking from heat and cold and zero abrasion resistant. It's always been
thought a butt connector caused no resistance, well that went out the window. Splice a bad wire
to a injector and have the possibility it wouldn't fire. A rain storm could cause nothing but
trouble. Bosch really had no procedure at the time for troubleshooting even the dealer was
stuck with very little training.

Really it wasn't till OBD-II that things took a turn, I remember very well GM's equivalent to
backyard throttle body injection-the electronic Quadrajet 4BB. Turd.

Some just don't realize how lucky they are to have a system that has written codes and
the availability of code readers and laptops. Walk up and plug in, wow that's tough. Although
it still requires some basic understanding of a CANBUS system.

Gomer Pyle--No I had my tin foil suit and coat hanger selection long before the rest of this tribe.
And I'm good at troubleshooting that crap. Below is a photo of the code reader we had back in
the bad old days. I'm still a mechanic

 

[DMiller]

All we had in the 60s 70s and 80s until OBD I was what is pictured and Oscilloscopes. ANALOG O-Scopes, Caddy came out with 'Digital Command Control" in their cars, Absolutely SQUAT on diagnostics even for their techs, they had to call Caddy Corporate for assistance.

 

[JD955SC]

"Have you updated the software to version xxxxxxx?"

I swear that's the equivillent of calling the IT department and they tell you to turn the device on and off again. 99% of the time it does nothing.

Many times I’ve started typing the reply I really want to send then have to walk away from my computer for 10 minutes.

Or my personal favorite reply, where after I put “Performed Action X per service letter/tech bulletin, no change in results” in my initial contact message and the first reply is “Perform Action X”. Come here, I just want to slap, I mean talk to you…

I swear the arrogance level of “these mechanics are just stupid grease monkeys” is so high they refuse to believe us when we tell them something, and funny you should mention IT because our IT department treats us the same way.

 

[Truck Shop]

I swear the arrogance level of “these mechanics are just stupid grease monkeys” is so high they refuse to believe us when we tell them something, and funny you should mention IT because our IT department treats us the same way.

It's not arrogance--it's a game they are playing to get you or someone else to do it for them.

 

[92U 3406]

Many times I’ve started typing the reply I really want to send then have to walk away from my computer for 10 minutes.

Or my personal favorite reply, where after I put “Performed Action X per service letter/tech bulletin, no change in results” in my initial contact message and the first reply is “Perform Action X”. Come here, I just want to slap, I mean talk to you…

I swear the arrogance level of “these mechanics are just stupid grease monkeys” is so high they refuse to believe us when we tell them something, and funny you should mention IT because our IT department treats us the same way.

I got the exact same treatment when filling out DSN's.

One smaller chain I worked at actually had a team of 3 or 4 ex-mechanics whose sole purpose was technical assistance. By far the best way I've seen it done, I could call them up any time during the day, bounce ideas back and forth etc. Always prompt and so much nicer than trying to communicate everything over text.

 

[Truck Shop]

 

[DMiller]

Unmistakable Cummins
Supercharge Unit?

Can still remember the wedding bands, get caps snug, bump crank back and forth to square them on the bolting.

Studded mains, eccentric W/P bore, OLD series, 190?

 

[John C.]

The Simpson multimeter made me remember that mine finally died about two years ago, A replacement was over $300 so I went to Sears, one was still open at that time, and bought the $78 dollar digital special. There is just something about a needle swinging back and forth that is so easy to understand and interpret.

Techs wear white lab coats, have university degrees and get seriously upset when the night janitor has swept the floor or dumped the trash. They cry like babies when they stub their toe or get asked to touch anything dirty. Those that I've worked around would dump a job at a hint of something tough and were the first to try to claim credit for someone else's work. I suppose we should start putting frilly collars on the coveralls of the techs now days. At least that way we would know who was trying to stab us in the back if we happened to make them look back by just doing our job. They used to be known as parts changers but that term is seen as derogatory now days. I'd hate to see some tech have their self esteem damaged.

 

[mg2361]

One smaller chain I worked at actually had a team of 3 or 4 ex-mechanics whose sole purpose was technical assistance.

Our company did this. Problem is, they put a kid with 2 years experience into the position. You can figure out how that is working out..... Last week, we just found out they put another one with , Im guessing, 4-5 years experience?? into the role of in-house technical trainer..........this should be interesting....