c/diesel-mechanics

That $38 coolant hose clamp cost me an engine rebuild wait, sort of

Bought a cheap worm-gear clamp off the shelf at AutoZone in Reno, it sheared on I-80 at 3am, dumped all my coolant, and now I only trust constant-tension clamps from the dealer, has anyone else stopped using those budget clamps after a roadside failure?

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the_holly•8d ago

Downhill brake test went sideways on I-25 in Colorado Springs

Loaded semi lost air pressure on the descent near exit 138, I had to pull the emergency brake at 55 and it locked the tandems, melted two tires before I got it stopped. Anyone else had a spring brake grab like that on a grade, and what did you do about the tire damage claim?

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nora_walker57•9d ago

Those cheap coolant test strips failed me on a 2020 Freightliner

I kept using the $8 test strips from the parts store on a 2020 Freightliner with 180k miles, and they showed green across the board, but the driver complained about hot running near Amarillo last week. Pulled the coolant sample and sent it to the lab, came back with high nitrite and low pH, the strips never caught it before the water pump started weeping. Anyone else had these strips lie to them or is this just a fluke with newer SCA packages?

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the_paul•9d ago

Air tool oil vs. ATF for stuck bolts, ATF won by a mile

I spent a whole Saturday last month fighting a rusted lower link bolt on an F-250. Hit it with PB Blaster, let it sit, no luck. Then I remembered an old timer telling me about using ATF and acetone, but I had neither in the shop. What I did have was a half bottle of air tool oil, so I figured why not. That bolt came loose in about twenty minutes of soaking and a breaker bar. Compared to the usual penetrating oil, the air tool oil seemed to creep into the threads way better. Anyone else tried this or am I onto something weird?

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garcia.tyler•11d ago

That $200 injector puller set saved my ass on a 6.0

Honestly I bought one of those fancy injector puller kits after fighting a stuck injector for 2 days with a slide hammer. The kit cost me $200 but it popped that thing out in 20 minutes without snapping the bore. Has anyone else used the blind hole puller attachment or do you just torch them out?

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jamiew53•12d ago

One shift at a rail yard in Ohio flipped my view on oil sampling

I used to think oil sampling was just paperwork for the office guys. Then last spring I got called out to a yard outside Toledo where a fleet of CAT 3406Es kept dropping lifters. We pulled three pans in one day and every sample came back with high copper, but the lab report said normal. The old timer on that crew told me to stop trusting the 500-hour interval and start sampling at 250 for that specific run. He showed me a bearing that was already pitting at 300 hours on the hour meter. That one conversation saved us from rebuilding four engines before fall. Now I take my own samples on every major job and I check the numbers myself before I button anything up. Has anyone else found that the factory intervals are too loose for trucks that idle a lot?

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sam_thomas•12d ago

Hit 300,000 miles on my old 7.3 today

Rolled past 300,000 on the odometer this morning while hauling a skid steer up I-5 near Tacoma. Truck's a 2001 F-350 I've had since 180k, and I still remember the day the previous owner told me it was 'just broken in'. I expected some major breakdown around this mark, but the only big fixes were an injector harness and a water pump back around 240k. For anyone else pushing high miles, do you track maintenance by hours or just mileage, and what finally did your engine in?

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val949•12d ago

A shop in Bakersfield changed how I torque heads forever

I pulled into this small diesel shop outside Bakersfield last month for a quick gasket job, and the old guy there watched me torque a head bolt with my usual pattern. He just shook his head and said, 'You're chasing the torque number, not the stretch.' He had me mark each bolt before final pass, then back off and redo it with a gauge. Cost me an extra 40 minutes, but now I check stretch on every rebuild, no exceptions. Anyone else had a veteran mechanic school them on something they thought they knew cold?

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hunt.nora•14d ago

The $60 injector puller I doubted earned its spot last week

I've been pulling injectors with a homemade slide hammer for years, figured spending money on a dedicated tool was a waste. Last week I had a 6.0 Powerstroke in Denver where the injector was seized so bad the homemade setup just bent. Borrowed a buddy's injector puller, got it out in 20 minutes without fighting it. Anyone else have a specialty tool they resisted buying that turned out to be worth every penny?

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grantf73•16d ago

Stop chasing leak-free with sealant on wet injector cups

In my experience, sealing a cup with any moisture on it just moves the leak to the next startup, and I've seen three shops redo the same 6.0 job within a month because nobody dried the cups with brake clean first, so has anyone else tracked failures back to a damp surface?

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wendyk56•16d ago

Hit 100k miles on my shop truck, saw something odd on the oil analysis

I rolled over 100,000 miles on my 2018 F-350 work truck last Tuesday, so I sent in an oil sample like I usually do. The report came back showing copper numbers way higher than the last two tests, which caught me off guard since I haven't changed anything about my maintenance routine. Turns out the fuel filter housing had a tiny crack letting a little coolant into the oil, just enough to skew the wear metals. Have any of you seen coolant contamination show up as copper spikes before, or was my lab just reading something weird?

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victorhill•17d ago

Copper injector washers vs the cheap steel ones, big mistake on my 3126

Ran a Cat 3126 in a Freightliner last month and figured I'd save $14 with steel injector washers instead of the copper ones. Torqued everything per spec, fired it up, and within 200 miles I had coolant in the oil pan. Pulled the head, the steel washers had crushed uneven and killed the seal. Copper conforms to the bore, steel just doesnt. Went back to the OEM copper set for $38 and it's been dry ever since. Any of you guys ever cheap out on washers or gaskets and regret it on a rebuild?

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bennett.mason•18d ago

Adjusted injector timing with a dial indicator instead of eyeballing it, actually worked

I've been turning wrenches for 8 years and always set timing by feel, never trusted the whole dial indicator setup. Last month on a 2007 Cummins in Nashville I finally took the time to mount the indicator and do it by the book. Took about 90 minutes extra but the idle smoothed way out and the engine lost that cold start rattle. Maybe it's just me but I'm thinking about doing this on every truck now, even the older ones where I thought I had the feel down. Anyone else switch to precision tools after years of going by ear? What did you notice different?

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mary_foster92•18d ago

That $800 injector puller I bought and used once, mostly to learn I didn't need it

Back in 2019 I was working at a shop outside of Abilene and kept fighting these stuck injectors on an old 7.3. I figured the fancy puller would pay for itself after one job, so I dropped $800 on it. Took me a full afternoon to set up and the damn thing still stripped the threads on the second injector. Ended up using a slide hammer and a piece of chain I had in my box, got all 8 out in under an hour. That puller has sat in the bottom drawer collecting rust ever since, and I still think about the parts I could have bought instead. Any of you old timers got a tool you bought once and never touched again, or am I the only one burning cash on paperweights?

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viola_ward•23d ago

That time a coolant line exploded in my face at a truck stop in Ohio

I was out near a Pilot in Lima, Ohio last month, doing a quick PM on a 2015 Freightliner. I just finished tightening the lower radiator hose, started the engine to check for leaks, and boom it burst right at the clamp. Coolant sprayed everywhere, all over my chest and arms, and I just stood there frozen for like 5 seconds. Ended up having to drain the whole system, replace the hose, and refill with 3 gallons of coolant right there in the lot. The driver was watching me from his cab the whole time laughing, which honestly made it worse. Have any of you guys had a simple job go sideways like that out in the middle of nowhere?

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felix_williams71•24d ago

PSA: I compared OEM injectors to cheap remans on a 6.7 Powerstroke and one was clearly better

Last month I put a set of reman injectors from a no-name supplier into my 2015 F-450, and after 400 miles one started knocking so bad I had to pull the whole rail again. I swapped in a set of OEM Bosch injectors and the truck runs smoother than it ever did, even with 180k on the clock. Has anyone else had remans fail this quick or did I just get a bad batch?

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elliotm70•1mo ago

Swapped to a magnetic drain plug on my 6.7 Cummins and got flak from the old timers

They said it was a waste of money and wouldn't catch anything real. After 3 months and 2 oil changes I pulled out a handful of fine metal shavings off the magnet - stuff the stock plug never would have grabbed. Any of you guys run these on high mile engines?

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the_elliot•1mo ago

Swapped from a socket to a crow's foot on a CAT C15 top fuel line yesterday, cut 30 minutes off the job.

Thought a crow's foot would just be extra tool clutter but that 15 degree offset gave me the angle to break the fitting loose without pulling the whole injector harness off - has anyone else found a specific tool that changed how they tackle tight spots?

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umar59•1mo ago

That time I unjammed a fuel injector with a PB Blaster soaked rag and a prayer lol

I had a 6.0 Powerstroke that started knocking like a skeleton on a tin roof after I let it sit for 3 months. I tried the whole 'run it hot and send it' thing but it just got worse. Out of desperation I wadded up a rag soaked in PB Blaster, shoved it over the injector bore, and let it sit overnight. Next morning I fired it up and the knock went away after 20 seconds. Has anyone else pulled some 'this will probably break it more' trick that actually saved them money?

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jessica_robinson23•1mo ago

Old timer at the shop told me to stop cranking injector bolts down so hard

I was always worried about leaks so i'd crank them way past the spec. He showed me 2 stripped threads on a head he pulled last week, learned my lesson real quick after seeing that.

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verawhite•1mo ago

Old timer at the shop showed me how to seat rings with a squirt bottle

I was struggling with a rebuild on a 5.9 Cummins back in March. Oil consumption was through the roof after 500 miles. Guy named Frank who's been wrenching since the 70s comes over, grabs a spray bottle full of ATF, and gives each cylinder a quick shot before the final fire up. Said he's been doing it since the 80s and never had a ring seat issue. Has anyone else heard of this trick or is it just old school voodoo?

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williamm82•1mo ago

Old timer taught me to check oil cooler lines first on a 6.0

Back in 2018 I was working at a shop in Spokane and this old guy named Pete rolled in with a Ford 6.0 that was puking coolant everywhere. I was about to start tearing into the EGR cooler and head gaskets when he stopped me and said 'son, check the oil cooler lines first, they're cheaper and easier.' I was skeptical but he showed me this tiny hairline crack in one of the steel lines that was just spraying coolant when the engine got hot. Took me maybe 30 minutes to replace both lines and the truck ran fine after that. I figure he saved that owner about 4 grand in unnecessary work. Has anyone else had an old school mechanic drop a simple fix like that on you?

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viola_ward•1mo ago

Switching to synthetic oil saved my Cummins after 200k miles

For YEARS I used conventional 15w40 in my old 5.9, figured it was fine. Then at 215k miles I started hearing a tick on cold starts, got worse over 3 weeks. Pulled the valve cover and found sludge caked around the rockers and pushrods, real bad. Swapped to full synthetic Rotella T6 and a new filter, now 30k miles later the tick is gone and oil comes out way cleaner. Has anyone else seen this kind of sludge buildup from sticking with conventional too long?

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emery199•1mo ago

Overheard a guy at the parts counter talking about injector copper washers

Stopped by the Cummins dealer in Tulsa yesterday and this old timer was telling the counter guy he always soaks his copper washers in diesel for 10 minutes before install. Said it helps them seat better and stops that tiny leak you sometimes get after a few hundred miles. I figured why not try it on my last injector swap on a 5.9, and sure enough no weepage at all. Anyone else do something simple like that before putting things together?

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charliestone•1mo ago

Took a gamble on a no-name injector puller at a flea market outside Tulsa

I found this beat up puller for 15 bucks at a swap meet near the river. Guy said it came off an old farm truck. Used it yesterday on a 6.0 Powerstroke that was siezed up. Worked just as good as my Snap-on one. Cheap tools can be a total waste but sometimes you hit gold. Has anyone else found a solid tool at a random yard sale or flea market?

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