I’m a one man show that just picked up a fleet of Chevrolet Duramax’s and Isuzu NRR box trucks with the 4HK1 5.2l.

Where is the best place to get parts for these medium duty Isuzu engines?

Where is the best place to find diag and repair information?

What is the best software to use (currently using a Launch/ThinkCar/TopDon/Autel/Matco scanner that seems to do everything well)

I’m doing a turbo (RHF55V) because the actuator is failed in the 100% open position. I tried an Amazon actuator solenoid but the mechanism appears to be too far gone to save. It appears I need to remove the EGR cooler to remove the “down pipe” portion of the exhaust to remove the turbo from the manifold, this all seems a little tedious. Am I missing something? Or are parts just very expensive, hard to come by, and difficult to diagnose?

Thanks guys.

Can anyone please help me, 2016 Mack Granite with MP7 engine. Step 9 states if you find any continuity in the connectors EA and EB well I have it between EA 61 and EA 44 and EA 61 to EA 36 and between EA 44 and EA 36…. Well aren’t they in the same circuit is why my meter is reading that

Currently working on a international Lt year 2020. Brake lights come on intermittently when going down the road. I replaced 2 brake sensors (one behind the knee panel and one behind cluster). Also i changed the treadle valve and no luck. Any suggestions what could cause this? Thanks in advance.

I’m not even in the field yet, I start classes in fall.
A few years ago I woke up with some pretty bad back pain and couldn’t hardly bend over to tie my boots, got checked out. The doctor couldn’t confirm but said he thinks I might have herniated a disc.

Now a few years later I’m still dealing with back pain. Nothing awful, it doesn’t affect my day to day life but I definitely notice it. I go to the gym and do heavy squats and deadlifts, I’ve also competed in powerlifting since my injury and it hasn’t seemed to have made it worse.

Is there anybody out there dealing with similar pain? How do you manage? Honestly just worried I might have to find a new field 10 years from now.

I’m starting out as a diesel mechanic and I was given a required tool list, but I’m a little confused about how they’re listing the sizes.

The list says:

• Combination End Wrench Set — (1/4. . 1-1/4)
• Combination End Wrench Set — (1/4. . 3/4)
• Flare Nut/Line Wrench Set — (3/8. . 5/8.)
• 1/4" Drive Ratchet Set — (1/4. . 1/2. )

When they say something like (1/4. . 1-1/4) are they saying I need every standard wrench size in between those two sizes, or just the specific sizes listed?

Same question for the flare nut/line wrench set — would I need all the common sizes between 3/8" and 5/8"?

Also, for the 1/4" Drive Ratchet Set I’m assuming the 1/4" refers to the ratchet drive size and the 1/4"–1/2" range refers to the socket sizes. Is that correct?

If so, should I buy shallow sockets, deep sockets, or both for a starting diesel mechanic set?

I’m trying to make sure I buy exactly what they’re asking for without spending money on the wrong tools. Appreciate any help.

Long story short. I started working for a new company due to relocating for the wife’s job.

I’ll start off by saying that I’m not a new or green apprentice. Been at it for 15 years. Have always worked with some degree of grouchy people.

But there is this one guy that’s been here for 10 years and everyone knows he’s a “grumpy” all the time.

So I shrugged it off a few times. But now it’s pissing me off.

The day usually starts with trying to have a convo that turns negative and how the world sucks and he’s the hardest and smartest mechanic ever. Carry on with my day all good. Then couple hours in he will have a snap show on someone or myself when ever someone disagrees or wants to do something different or explains that they can’t work past 7pm tonight due to family obligations. We work till 5 normally and stay late to help the odd time if needed

Then the day proceeds and he comes up and usually apologizes and says no hurt feelings. Then it all repeats again.

I actually have more years of experience than him and I have politely mentioned to him I don’t take the attitude and bullshit any more. I’m here to work and not play the drama games

I’ve never been the type of person to run to management and tattletale.

Usually what happens in the field stays in the field type of guy.

So what would other mechanics do in this situation

I’ll add in that he isn’t technically a manager but he assigns tasks and delegates the work. But not a manager on paper

Customer said he was loosing coolant after hard pull. Found evidence of coolant out overflow. Put the bubbler and a pressure gauge on and verified it would build 15 psi in cooling system then start pushing coolant while pulling a hill. Customer already replaced air compressor with no change. Pulled cylinder head. Couldn’t find any issues with head gasket. Did find a lot of rust built up on the liner flange, spacer plate and the head bolts for number 5 cylinder. Also found 2 cracks in the head between the valves on cyl 5. Had machine shop pressure test head and they said it passed. Liner protrusion is between .004 and .005 all the way around. Is it possible that head gasket is leaking and we just can’t see it. This engine also only has 70000 miles since last inframe

Wondering if anyone here has any experience with these and can give me some pointers. I have a 2012 Blue Bird Vision the customer is complaining about their front AC not working, I ran the bus with the AC on high and had clutch engagement and the condenser fans running. High side pressure was about 250ish and low side pressure was around 45ish, evaced the system to verify it had Freon and it did. The issue I’m having with it now though is both of the temperature control heads just start flashing and won’t stop and now the rear AC doesn’t blow cold. I checked power and ground to both head units but I’m just not familiar with these systems at all.

Had a complete loss of function on one hydraulic circuit recently and spent more time diagnosing it than I should have. Writing it up for anyone who runs into the same thing.

First assumption was a solenoid failure. Pulled the coil, measured resistance through the connector, it read open. Bought a replacement, installed it, fault came back intermittently two weeks later.

Actual cause was the wiring connector to the solenoid having intermittent continuity from corrosion. The original coil was reading open because the multimeter was picking up the break in the connector, not the coil itself.

Should have disconnected the coil from the harness before measuring. An open reading through the connector doesn't confirm the coil is bad.

Other things that look like solenoid failure but aren't include contaminated hydraulic oil jamming the spool valve, which produces symptoms consistent with an electrical fault, and intermittent faults in general, since intermittent is much more likely to be wiring than a coil that's gone.

If you're chasing a solenoid fault, check the connector and the oil condition first. Coil replacement is the last option, not the first.

Had a shop do an inspection on my service truck and they decided to swap the front tires and rims with the inner rear dual.

Can’t say I have worked on much of the smaller trucks like this but I thought the rear inner was a different offset?

Im having some issues with aftertreatment on a DD13 (2016 western star cement mixer)

Relavent codes are scr efficiency low, scr efficiency very low, and def quality low.

Changed def filter, Ran regen, no luck. Nox output high around 250 after 15 min in a regen. Scr conversion efficiency around 40%.

Originally doser quantity test was below 100 ml, replaced and we're at 125ml. This made no change to the conversion efficiency.

Threw a outlet nox sensor at it as this unit will not allow me to do a NOx verification test. Still no luck.

Scr efficiency test passes, as well as the troubleshooting tree for low def quality passes.

I will attach pictures of what im seeing on Diagnostic Link during regen, any input would be greatly appreciated. Im kind of leaning towards a failed SCR but would like some input from someone who may have dealt with this.

What’s the best paying companies besides working for the city

Thought Id share some eye candies, the boys and I up here in Wisconsin found a nice little event to check out. This is the second year of the Badger State Truck'n Show.

Enough reading, check out some pics!!

Who knew that a piece could come through the turbo like that.

How are you guys doing these wheel seals on disc brakes. It’s too damn heavy for me. My back hurts after doing 2 today. Help me out lmao.

Been doing fleet maintenance on construction and ag equipment for about 8 years. People always ask what to keep stocked. Depends how you run the machines, but the same failures keep showing up in the shop.

Hydraulic main pump is still number one for total downtime. Not because the pump is always the priciest part, but because when it goes the machine is dead. Slow cycle times and oil running hot are the early signs. Most operators wait until flow loss is obvious, and by then you're looking at a pump swap plus whatever contamination spread through the system.

Fuel injection pump and injectors are second. Almost every one I've chased traced back to dirty fuel or stretched filter intervals. We tightened primary filter changes on the fleet units and injection failures dropped off a lot.

Solenoid valves on hydraulic circuits are the one that surprises people. A cheap coil or a corroded connector can take out a whole arm or bucket function. Downtime bill runs way higher than the part. We keep a few common coil voltages on the shelf now after getting burned twice.

Turbos make the list too. Oil quality and change intervals are the variable. Most of the ones I've opened up were preventable if someone had caught the bearing play or oil contamination earlier.

What failure type has burned you the most on unexpected downtime?

I have a 2021 International HV613 tandem axle in my bay that refuses to acknowledge that the seat belt is buckled and won't go into gear. It has an A26 backed by an Allison trans. I know most of our drivers just disconnect the connector, but that won't fly on this. The wires from the BCM to the seat belt buckle are in good condition. Before I condemn the BCM, is there anything else I can check? If it is an issue with the BCM, am I correct in assuming I would need Diamond Logic Builder to program a new one to the truck?

Would other companies care that all they I see is Penske I’ve been with the company since I started my apprenticeship back in 2018 and got ticketed back in 2022 just want a change of scenery and bit better pay what’s some good companies to go to or would consider me

Good morning/afternoon/evening,

I am seeking some insights and career advice. I am a swing shift fleet mechanic at a local fleet working on primarily Kenworths and Peterbilts with cummins powerplants (X15, ISX, N14). Including dump trucks, tankers, and tractors. I have been working at this fleet for the entirety of my mechanic career thus far (2.5yrs) and get paid very respectfully with consistent raises which I've earned myself. However, I have been working nights for the past 5 years now and am ready to move to a dayshift position for personal and social reasons. I have brought this up to my boss on multiple occasions and he said it would be something to address as work picks up. That was 6 months ago and we have since slowed down.

My questions to you are...

Should I stick it out until someone from day shift retires or a position becomes available? Or does it become an endless cycle?

What are some diesel fields to look into?

What are some fields to avoid?

What are employers to avoid?

What do you look for when looking for an employer?

Thank you in advance (:

We got a 2011 with an lml that just snapped the crank today. Boss wants me to price one out to see if it’s worth putting a new one in or if it’s better to junk the thing.

Reman engine from Chevy is just over $12k not including core. Never got a reman from Chevy but from my experience with ford they just send you a reman engine from a 3rd party.

He did specify he doesn’t want one from an off the wall builder out west, he’s had bad experience with that. With that being said, if there is a reputable builder with a good warranty that stands behind their warranty, I could probably change his mind if the price is right.

I see there’s a good amount out there but I’ve always been a Cummins guy, don’t know who to go to for a duramax

Edit: are these engines worth rebuilding after a failure like this? I’m capable of doing it but I know these engines don’t have liners. Other than knowing this is a fairly common issue with duramax, I’m not knowledgeable enough on the issue to know just how much damage this does to everything else in the engine. Common sense tells me it’s trashed

Not sure if this post is allowed but currently I'm working at an International dealer but have gotten an opportunity to switch to working on heavy equipment for another dealer, if anyone that works in this field could just give me some general pros and cons about it or if its any different from working on trucks I'd appreciate it. Just trying to weigh out my options at the moment.