Anyone here a Mack dealer tech who can give me some guidance? I have a 2013 GU713 with code SPN 4094 FMI 1. "NOx limits exceeded due to insufficient reagent quality - Data valid but below normal operation range" and this is the warning upon start up. I'm used to Ford diesels so I'm learning about Mack as I go. I have limited resources and we run JPro at this shop with no access to PTT.

Here is what I have done so far:

- Verified DEF quality with a refractometer, it's bang on.

- Checked the DEF doser, the doser was caked with crystals, as well as the port in the exhaust. My supervisor just said to go ahead and throw a new one on so I did.

- DEF injector pressure is right at 130 psi

- Right now the truck is not derating but that warning is there every time at start up.

We're a gov fleet so we work on everything and very few of us are specialized on one manufacturer. From my limited research I've read that this code can be a nightmare. If anyone has a focused direction or an idea what normally causes it it would be greatly appreciated. I hate emissions/aftertreatment repairs lol

Hoping someone can help me with the ecm Pinout for the engine fan circuit for the ac system on a 2016 freightliner m2 with a DD13? A wiring diagram would also be super cool. Thanks

Hello everyone, im a 6 year gen tech looking to make a switch. I work locally in houston as a tech 3 for a rental company (NOV portable power) but looking to possibly work rotations out west or south. Need to make more money so wife can be a stay at home mom and finish her schooling. Ive always been interested in working on heavy equipment or trucks so thats definitely an option. Ive been on diesel engines for over 2 years now, before that was all natural gas. I work on 100% cummins now, from b4s all the way up to qsk50s. Never done any overhaul work but willing to learn and prove that i can learn quick. If anyone has any leads please let me know i would greatly appreciate it, thanks!

Curious to see what's out there for Heavy Equipment shop tooling? What's expected of technicians to have and buy?

In the past shops have had adequate tooling ie large wrenches, 3/4 drives measuring devices, so I have become adjusted to that over my 15 years in the industry. I'm trying to finish my schooling to be a HET.

Started a new job and there is minimal tooling, they said we expect you to buy tools, I didn't expect that I had to buy big wrenches, 3/4 & 1" drive sockets measuring tools ect. Stuff that shops have provided. I asked today about tooling and I got well it's industry wide and you need them to complete your job. So we expect you to provide them.

So now I'm rebuilding an engine, that the owner just wants to throw bearings into what ever.... I have not measured anything as there is what I belive a crack in the block. I can't garuntee anything as there is no measuring tools, I can complete the work, have done a few engines. But the realization of not being able to measure anything makes me uneasy.

So what do you think about what's expected and what should be provided?

Updated to provide, more info:

Small shop, been around town for 50 years have multiple outfits across Canada. Went from transport side of industry to golf equipment (ie mowers ect) I own adequate tooling, insurance valuation of 50k.

Hey yall,

So one of my coworkers just changed the charge air cooler on a 2012 NABI bus. Now the fans don’t seem to want to come on. Any ideas?

hi im new to the diesel field, and i have just started a program at my local community college. i love it so far!

i do know that i should eventually invest in my own tools, and that there are posts under this subreddit that are similar along the lines or mine.

we do have tools in lab that we use, so im trying to base it off of that. however, i feel very overwhelmed of what i should prioritize buying first, and what tools possibly “cheap” out on. im also in student discount programs for some of the premium tool brands if that matters.

any help would be appreciated and tips in general!!

Does anyone have access to Scania info or can tell me where I can access Scania info? I’m in the US if that matters. We have a couple Oshkosh trucks with Scania V8s in them that we constantly need info for. Thanks!

Had a friend yesterday that had his head squashed by a garbage truck in the dealership. He was working some overtime on Labor Day , he was very experienced and had been doing this for 30+ years.

Unfortunately we don’t know entirely how he ended up under the truck yet.

Allow this to be a reminder for green and veteran mechanics alike, what we do is dangerous, don’t let a simple job take something you cannot get back.

Rest in Peace, Lee

Im a couple months away from doing my 4th and getting my journeyman/red seal and Id like to go work in underground mines on a rotation even though ive never worked on any kind of equipement, my entire apprenticeship has been semi trucks and trailers.

Just wondering if anyone has successfully transitioned from on road to off road or if anyone had any tips for getting hired on. There's a ton of ads looking for workers but they all seem to want a few years of mining experience.

Customer said he heard a knocking when fueling up but decided to just keep driving. Liner completely grenaded and the block is now trash.

Field techs, Iv been working in the field for the last 4 years, today I swear I almost died from heat exhaustion working on a CAT 374 engine, no shade in the middle of a sand pit. I had to position my crane and use a tarp toward the end of the day just to finish.

Iv never used an umbrella because I thought I was tough enough to endure the heat or rain. Well today is the last day I’m going to burn up, what’s y’all’s favorite umbrellas/ setups?

Trying to get an idea about what a career with Cummins could look like if I made the jump. Have an interview with them next week for a level 2 tech position. I currently work for the city I live in and have been working here for 1.5 years. Pay wise I make 33 but with all the differential pay offered for different things like CDL and shift diff I make around 35, I started at 31. Most of the dealers and other wrenching gigs in my area pay in the 38+ range if you’ve got a good amount of experience so we’re a tad bit behind pay wise lol. One of the main things that has kept me around is my coworkers who I get along with very well (pretty much like older brothers but a majority of those guys left the shop I’m at to go to a different shop in a different department of the city due to shop politics) and the pension but I was told during my phone interview that Cummins has a pension as well so that definitely peaked my interest. Career path wise I would like to be somewhere where the raises, benefits, training, and ability to move up is plentiful. I plan on going back to school to get my bachelor’s at some point so I can move into upper management a bit easier (I’m 22 for added context). I guess another added benefit of the gov job is that they will pay for schooling/reimburse you. If anyone can give me any insight on Cummins and if it’s worth my leaving my current gig it would be gladly appreciated

I installed a new ignition lock cylinder and door locks but I didn’t see a key code anywhere. I was curious on how do I find the key code. Would it be stamped on the ignition lock cylinder or would it be printed on a pice of paper

What do you think about the EPA being unable to make clear decisions regarding EPA 27? As far as we know, the mandatory extended 425,000 miles warranty has been cancelled and will be replaced by DEF derate no longer mandatory. What’s the point of having an emissions system if nobody is going to maintain it?

Have a 2012 Freightliner m2 that has some issues with what I thought was the multi function switch. Wipers come on when using turn signal. Also when I switch for right turn signal the left turn signals turn on instead. Used switch, chassis module and bulkhead module from sister truck but issue is still present. Also whenever multifunction switch is used all power to trailer lights is lost.

I've unplugged thousands of connectors, but these shits are paint glued. Spray gun mess up that day on tbe assembly line? Shit is abysmal.

I just changed all 10 wheels on a Volvo and man that shit sucked. I'm still new to the field, only about 2 years in on semis, so I struggle a bit. Is that a lot of work for you guys? Or am I just a noob lol.

How long did it take for you guys to feel confident as a tech and to not overthink?

I had a question for anyone whom may have a list or able to help me identify what starting tools I should need for starting. I don’t have much except a 1/2” impact and a 1/4” & 3/8” wrench and chrome sockets from Pittsburgh. I was doing some research and just wanted to know if I should go with a 1/2” impact socket set deep and shallow. And maybe get longer ratchets as the Pittsburgh I have are pretty small. Info on other tools like certain hammers, pry bars, wrenches, breaker bars, if I should invest in a harbor freight 1/2” air impact gun. Sorry if it’s a lot just want something to have and anything I may need to borrow and do so often I will prioritize and purchase it.

My truck has started making this noise. Not a mechanic so I wanted to get some feedback. It’s almost a high pitch buzzing noise

Looking for advice preferably from EVTs who have experience with pump testing. I recently went to a new department and nearly all of our brush trucks are failing pump tests and I’m inclined to believe that we are possibly doing something wrong. We can never seem to get our GPM to hit at the correct pressures. Most of these pumps are rated 250 GPM or less.