~~~~~School Bus Mechanic

The Mechanic Red Seal Journey

2013-05-20T18:07:00.002-07:00

Mechanic Red Seal Certification

The coveted Mechanic Red Seal is the culmination of a four year apprenticeship and on-the-job experience. I never forgot about the people I worked with who took the time to explain how systems worked and the best tools to use.

The stepping stones to achieving your Mechanic Red Seal will vary depending on fate and possibly luck in some cases. Above all don't stop trying and show your true colors to perspective employers. Stay in contact and don't allow them to forget your face.

Attitude is everything. Every year our shop accepts a commercial transport pre-apprentice for a one month practicum. Every one of these guys are energetic, respectful and humble. The college instructor hand picks these 20 something future mechanics and it's very easy to work with them sharing over 100 years of combined experience in our shop.

There is a difference when working in a fleet shop compared to a customer shop. However there's no rushing around making quick decisions for the sake of saving time and money for a customer. A fleet shop has spare units to hand out and when it comes to our school bus fleet we can not cut corners for the sake of time. Transporting children means special attention on safety.

There are so many mechanical fields available. When I apprenticed the commercial transport and heavy duty trades was combined. We covered trucks and earth moving equipment so the curriculum was very broad. Now those two areas are separate trades and specialized. Just having a journeyman ticket doesn't mean you qualify for everything available. There's mining, construction, trucking, automotive, logging and so on. Pick one and go for it with the most enthusiasm you can muster.

Mercedes 900 Diesel Engine Runs poorly after fuel filter change

2013-03-25T22:56:00.000-07:00

The Mercedes MBE 900 Diesel Engine. What I have experienced since we acquired these engines in 2005 is they are built well and stand up to the rigorous start and stop routines involved in a school bus fleet. The pre 2007 engines are not emission controlled like they are today and have given us very little grief. However I would like to share a tip on a troublesome problem we had with a 2005 freightliner conventional school bus.

The Video I made above explains how to properly bleed these engines. Strangely enough we were told to crank over the engine continuously after a fuel filter service until the engine fuel pressure built up. At first we were scratching our heads thinking we're living in the new millenium and this diesel engine has no priming pump and only one starter...that was destined for failure eventually from the constant load it would have to endure turning the engine over and over just to prime the fuel filters.

We tried to innovate and pressurize the fuel tank and crack a line at the secondary fuel filter to help the system prime up faster. Unfortunately some of our new buses had fuel guage sender problems and there were buses running out of fuel out on the road. There was no choice but to load the hell out of the starter to get it going again.

By the way if you loosen the fuel line from the unit pump to the head the line must be replaced. Recommended by the dealer / engineers. We were forced to crack the lines only once and re-tightened them after start up and did not have any leaks. So I imagine the odd time the fuel line will not seal properly after it has been disturbed?

Engine Runs Poorly After Changing Fuel Filters

We recently experienced a problem with one of our MBE 900 diesel engines after a fuel filter change. It ran poorly and was not picking up fuel. It eventually kicked in and ran fine for a few days. However it died on it's bus run and had to be towed. It ran like it was starving for fuel like air in the system. The engine would idle fine but crap out under a load.

One thing noticeable was when priming the fuel system with the pump kit the pump just kept filling the lines and filter without the typical solid feeling at the pump handle indicating the system was primed and ready to go. Eventually the Mercedes diagnostics instructed us to check the return fuel volume from the head and the unit pumps.

There should only be 1.7 Liters of fuel returning to the tank every minute at an idle. We had double that...so it ended up being the overflow valve (similar to a check valve) which is in the return fuel plumbing to maintain around 60 psi. It was not doing this and caused a loss of back pressure in the return system which caused the hard starting, rough running condition. Now our shop will recognize the problem after these symptoms pop up again.

Special Tool Saves Components When Welding

2013-02-24T15:53:00.001-08:00

Protecting Vehicle Components While Welding

This tool (Ultra Pro from Napa) is what we use in our shop and has worked successfully for us for several years (click on photo to enlarge). I was asked what kind of coverage is available if it fails and a component burns out because of it from a high energy surge from welding.

Not sure about that question; I contacted the selling dealer and they have not come up with any answers. The other option is to disconnect the battery ground when welding. The only inconvenience from this is you have to reset your digital components like clocks and timers. Modern School Buses have several modules within the multiplex system and using either one of these precautions is mandatory to save an expensive component from failing.

I have not replaced any modules in our buses yet; the main problem being corrosion to wiring and connections. The connector plugs still get moisture inside in some cases and the use of dielectric grease helps a lot to keep moisture away from the terminals. Oxygen, moisture and electrical current can team up nicely and corrode connections quickly and cause trouble.

A lot of times I have found with corrosion on module connectors there are cross electrical signals that occur and some circuits get energized with constant battery power. We had an instance where 3 different circuits were operating on their own even with the ignition shut off.

With the wiring diagram we were able to determine where the circuits started from and it led us to a corroded connector at one of the control modules. As a preventive maintenance step we have applied dielectric grease to all of the module connectors.

Diesel Engine Exhaust Defining Different Smoke Color

2013-02-17T12:33:00.000-08:00

A Smoking Diesel Engine

What Do The Different Colors Of Smoke Mean?

Thank you to the us.gov EPA Dept.

The color of the smoke coming out of a diesel engine that's not running properly or showing signs of poor mileage can tell you a lot and is the first step when you start your troubleshooting process. Smoke colors to take note of are black, white and blue.

Since there are so many different diesel engine manufacturers and configurations the plan of attack depends on the engine model especially when dealing with the fuel system.

When there is an imbalance between air and fuel meaning too much fuel or not enough air induction Black Smoke will occur. Checks you can perform:

* Check the air filter for a restriction.
* Check for faulty injectors or injector pump.
* Check Turbocharger boost reading or inspect for any failures (turbine / compressor wheel)
* Check the cylinder head valve adjustment.

White Smoke means there is inefficient combustion within the engine cylinders.

* The engine timing or injection pump timing could be out of spec. or there is an internal failure
* Air in the fuel causing starvation to the injection system.
* Low engine compression
* A Possibility of water in the fuel

NOTE:
* If you get coolant loss and white smoke that will indicate a possibility of a faulty EGR or "hopefully not" a cracked block. There are several others mishaps that could happen these are just a couple examples. Case in point: We have an engine with a cracked block that was using excessive amounts of coolant and blowing white smoke out the exhaust. This is where an oil sample really comes into play. A high level of sodium indicates coolant in the engine oil.

Blue Smoke The term "burning blue" is well known and that's caused by excessive engine oil getting into the combustion chamber.

* Worn compression rings or oil rings
* Worn cylinder bore causing blow by and excess oil to enter the cylinder
* Engine crankcase over full
* Oil entering the fuel system

Of course this is very general and is meant to get you thinking when the smoke develops more than usual. cold starts in the winter season will produce white smoke which is normal. This will clear up once the engine reaches operating temperature. The diesel engine is your friend as long as you jump on small problems before they get bigger. :)

How To Find A Good Mechanic Review

2013-01-07T16:29:00.001-08:00

I recently read an article from my regional auto association BCAA (British Columbia Auto Association) and they covered the topic on how to find a good mechanic. After reading it I had to agree with all the tips they had pointed out. I'll go through them here and you can comment at the bottom of this post if you have any thing to add.

Let's face it finding a good mechanic is a challenge and honesty would be on the top of my list. Here are 6 tips from BCAA.

1.) Get feedback, ask around. It doesn't hurt and doesn't take a lot of time. Friends, relatives, and co-workers are a good source of recommendations. See which shops and technicians they’ve had good experiences with. Word of mouth is extremely valuable and talking to someone who has had a positive experience at a repair shop or have a regular shop they frequent because of a great relationship is one of the best ways to find a good mechanic/shop.

2.) Check credentials and reputation. Ask the shop if the technicians working on your vehicle hold a certificate of Trades Qualification or equivalent credentials. Also, research the shop’s record and rating with the Better Business Bureau. Having Mechanics with their Provincial tickets (Canada) is essential. You don't want unqualified people getting their first hand experience on your vehicle especially if you're paying a shop rate!

3.) Ask questions. This is a trust issue. If a shop mechanic takes the time to fill you in on details that's a very good sign they aren't hiding anything. Don’t hesitate to tell the service advisor that you’re not sure what something means, or ask them to explain it further. Also ask the service advisor to physically show you the problem on your vehicle. This will give you a better understanding of the issue. Any mechanical repair shop that does not want to show you the old parts off your vehicle is scamming you.

4.) This is a huge point...Get estimates in writing. Verbal estimates can be disputed or forgotten. Always get a written estimate prior to approving work on your vehicle and insist on a call if repair costs exceed the estimate. Most estimates allow up to a 10 per cent overrun. Request a call if costs exceed this allowance. This makes sense and most shops will advise you if there is a cost over run.

5.) Cover yourself down the road and make the repair shop accountable if they replace or repair anything. Ask for replaced parts. When dropping your vehicle off for service, tell the shop you want to see any replaced parts. In some cases, you are entitled to keep these parts, unless the facility must return them under a warranty or exchange program. Replaced parts and a well-documented repair order can be useful if there is a problem later. "get it on paper" there is no way any shop or mechanic can BS their way out of a dispute if you have the their black ink on your white paper invoice.

6.)CYA "cover your a--" Get a detailed copy of the repair order. Make sure it specifies the costs of labour and each part. Ask for the facility’s warranty in writing if it’s not printed on the bill. BCAA approved facilities offer a 12-month/20,000 km warranty on new parts and labour. More reason to join an automobile club. I used mine to fish keys out of my car and that alone paid for the one year membership fee.

Here's a handy video with more detailed tips on locating a reputable repair shop and trustworthy mechanic.

Check this link to a site called Rank My Mechanic where you can search ratings from other people on mechanics from all over. I haven't used it but it looks like it would work well if it applied to your area.

Diesel Fuel Injector Basics

2012-12-22T21:22:00.000-08:00

This is the best video I have ever watched on how diesel fuel injectors work. It covers hole and pintle type injectors that are actuated hydraulically by the high pressure fuel injection system. There are so many different injection systems in the industry it would take a lot of posting to cover them all.

The basics is all you really need to know to get the right idea on how diesel fuel injection systems function. Most Mechanics don't specialize in the fuel injection field primarily since it takes a ton of very expensive testing and calibration equipment to repair injectors and pumps.

The main principle noted in this video is the injector is seated by a spring. When injection occurs the high pressure fuel is routed to the body gallery of the injector next in the firing order and overcomes spring pressure lifting the seated needle allowing high pressure fuel into the combustion chamber.

When the injection cycle ends the spring in the injector reseats the injector. The mechanic must troubleshoot modern diesel engines with software compared to years ago when you could crack a fuel line one at a time to find an engine miss on a mechanical fuel injection system.

With today's electronic diesel engines a laptop armed with software is the only way to find a problem. Watch the video and you'll get a much better idea through animation how diesel fuel injectors work.

Cummins ISC Diesel Engine Repair

2012-12-07T22:12:00.000-08:00

Our latest Cummins ISC diesel engine repair involves a broken valve spring that caused the push tube to bend and the valve lifter to break apart. It damaged the camshaft lobe so everything from the head down to the camshaft has to be removed for replacement and repair.

The head and camshaft have been removed. The head requires repair so we sent it out to the local machine shop. We are replacing all the valve springs and valves to play it safe.

Here is the damaged valve lifter beside it's mate. The sharp edges scored the camshaft beyond repair. Surprisingly the cam was under $300.00 which is cheap when you price out other various diesel engine parts.

This is the bad camshaft lobe caused by the failed valve lifter. The only way to replace the lifters is to remove the camshaft. The lifters are installed into the bottom side of the engine block so they have to be held in place with doweling from above. If you have any experience with the Cummins ISC diesel engine please feel free to contribute.

I'll post more on this job in a future post. Please comment if you have something to add.

Mechanics & Diesel Engine Technology DPF out of range high engine code

2012-12-01T23:05:00.000-08:00

The days a Mechanic can get out his screwdriver and tweek a diesel engine are gone. Yes it's 2012 and times have changed. 2007 was a year I won't forget. Emissions on diesel engines were fully operational and ready to provide us with cleaner air. I totally agree with this mandate but new technology has created a lot of headaches for us old school Mechanics who just want to fix the problem and never have to fix the same problem again.

If an engine farts the wrong way an engine code pops up. The parameters are strung as tight as a piano string so a minimal buildup of soot or carbon within the exhaust system and you're in for a challenge. However if you have the laptop, software and experience it gets easier. That's the good news....the unfortunate part is you'll need deep pockets to keep your engine fine tuned and code free.

We just had our first run with one of our 2007 Mercedes MBE diesel engines that just ran out of warranty. All this new terminology I'm going to tell you about is focused around the muffler. The code was "DPF out of range high". This means the temperature or pressure at the sensors were not in their acceptable ranges. They are located right at the DPF "diesel particulate filter" (muffler) and tell the computer that there is a blockage starting to accumulate in the dpf cartridge/filter.

The on-board computer monitors this system and carries out automatic regenerations as it sees fit. A regen heats up the exhaust system to high temperatures and cooks the particulates out of the exhaust system without contaminating the environment. This works great and will give you trouble free driving for quite a while, however over time the regeneration process needs to be forced using your laptop software with the Mercedes MBE 900 diesels.

This is easy to do and can be done every second oil change or when required according to how hard the engine is worked. The longer it runs at operating temperature the better, because of the constant heat there will be less build up of particulates.

So getting back to our problem we checked the software for the last time the cartridge was serviced and it had been done once. It was not replaced but cleaned out 2 years earlier. By the way when you service the cartridge you must enter the details into the engine software records. So we replaced the cartridge which can easily be done on the bus by removing 2 clamps. It comes with gaskets as well.

Once the codes were deleted and the bus was road tested it came back clean and we were elated that everything worked out OK. So now we know what to do with that particular code, check the wiring, make sure you're getting a 0-5 Volt signal to the sensors and service or replace the DPF the cartridge. Recommended cleaning or replacement is 150,000 km. for this particular Mercedes diesel engine. If you've had some experience with this please leave a comment :)

Commercial Transport Mechanic In The Making

2012-10-27T22:39:00.002-07:00

Every year we accept an applicant from the local college who has just completed a 10 month pre-apprenticeship class in the commercial transport program. Becoming a mechanic in this field takes a certain amount of enthusiasm and positive attitude.

Taking advice wisely and showing your humble side is an asset when just starting out. The mechanics in our shop are always willing to share their knowledge which is invaluable and will help recipients get a good base of knowledge possibly preventing mistakes down the road.

Experience is the best teacher in my mind and working with a great mentor will excel your knowledge ten fold. We gave Jason a thorough one month practicum filled with servicing, brake jobs, suspension and electrical repairs. He loved the hands on and commented that getting into the actual work was far better than sitting in the classroom. Not to take anything away from classroom learning but his comment is the general consensus with a lot of mechanics in the field who are in the trade to work and get greasy.

At the end of the month I was pleased with Jason's performance and he was happy with his experience in our shop. Interacting with experienced mechanics is a great way to get a feel for the commercial transport trade. Until next year I am looking forward to the next up and coming commercial transport mechanic who shows up at our door.

Mechanic Troubleshooting Tales & A Blast From The Past.

2012-09-29T22:30:00.002-07:00

When I was a 2nd year apprentice Mechanic in the late 70s I left the mining world and got a job up north at a busy truck shop, the oil patch was booming and Mechanic jobs were easy to find (even for rookies like me). The shop rate was $27/HR and I was pulling in $10/HR. If there was one mechanical problem I resisted (no pun intended) the most it was electrical faults.

I'll never forget a White Western Star that came in and it had positive ground, you had to reverse your train of thought when it came to thinking through the circuitry. Anyways, back then series parallel switches were very common (12 volts running voltage and 24 volts cranking voltage). You just had to remember how the wiring went back together while the customer was standing there looking at his watch.

Through all that experience up to now and hundreds of shorts, no starts and charging system problems I've come to one conclusion.

Keep it simple and don't over-think the problem. If wiring continuity is disturbed with resistance, short or open circuit you're going to have trouble.

SIDEBAR: If you ever have one or more circuits either not working or operating sporadically with relays or solenoids clicking on and off, there is a very good chance you have the blue stuff (corrosion) making a home in the connector or inside a module. It's happened to our equipment many times. The environment will take down anything that exposes itself!

If you look at an electrical system and think too broad you'll lose yourself. Think of the fault and the circuit, nothing else. A human friendly wiring diagram is most essential!

Here is a perfect example of a wire that had rubbed through the insulation. Oxygen goes to work fast on this exposure. Luckily this problem was obvious to the human eye and not nestled inside a connector or module. One other method we use is grab the wiring harness while the fault is active and shake the hell out of it. Sometimes this works to fish out a problem. A short might all of a sudden quit or an open circuit might reconnect while you're at a certain point at the harness or at a connection point.

As Mechanics we can learn and adapt as we go through our training and experiences. Get your hands dirty and you'll get more tuned into any kind of mechanical problem.

Did you find this information useful?.....Please share this post.

The School Transportation News Vlog

2012-09-20T21:51:00.000-07:00

Editor's Note: The STN Vlog covers recent news concerning the school bus industry. The topics discussed are interesting and informative. I've placed the home page link below for STN. The mechanic information I get off their site is priceless with new technology on green energy and the latest mechanical engineering plus research and development. Below are more details on what will be covered in the Vlog below.

*School Transportation News Editor Ryan Gray goes into detail on NTSB's recent release of its investigation report on the March 12 crash of a motor coach in New York City.

*GK Design's fresh concept for a next-generation school bus.

*He also discusses the showing of the documentary La Camioneta at the Central American Resource Center where STN spoke with Arturo Zepeda, Community Organizer, and Juan Carlos Lopez, Immigrant Day Laborer.

*Lastly he talks about the viral video of New York school bus monitor Karen Klein, who was verbally assaulted by a group of students on the bus.

If you want to know more about school transportation news go to http://stnonline.com and check out their site. You will find a lot of extremely useful info on the latest technology and innovations along with special reports on what's going on in the school bus transportation industry.

Setting Diesel Engine Valves Using The Rocker Method

2012-07-22T20:34:00.000-07:00

Setting Diesel Engine Valves Using The Rocker Method is possible on any Inline diesel engine which are built the same in many ways. The pistons are matched in pairs to the crankshaft throw...so two pistons reach Top Dead Center together.

Since one will be on the exhaust stroke the other cylinder will be on the compression stroke and the valves can be adjusted accordingly.

I was having some fun with article to video software today explaining how to adjust valves using the rocker method..... the video is done in text format only. There's some funky music to go along with it so I hope you get a kick out of it :)

This type of procedure is handy if you're in a pinch. Just recently I had to adjust the valves on an Inline-4 Isuzu Diesel Engine and used the rocker method once I had the valve lash specs.

2012-07-15T12:52:00.003-07:00

Comparing Synthetic Oil to Petroleum Based Oil.

To compare synthetic oil to petroleum based oils might be be a waste of time but it's important to find out a few details to insure us that the extra expense is worth it. Regarding our automatic transmissions that was the first consideration in our fleet...the cost was 4X higher than regular Dexron III and IV.

We had experienced some clutches wearing out on severe runs around 2005 and can't say either way if it was the the transmission design back then or the Dexron petroleum based oil causing this problem.

We switched over a several years ago and all our transmissions are now running synthetic oil. I'm happy to report that since then we have not had any mechanical failures and decided to change oil every 3 years for all units ....keeping it simple within our PM program.

We are running 74 buses with Allison 3000 and 2000 models so switching over was pricey. The instructions we got was to drain the Dexron and fill / run the transmissions for 30,000 KM then drain and refill again with synthetic.Newer buses we ordered with Synthetic oil from the factory.

Lubrication
Synthetic oil changes viscosity very little during various temperature ranges while petroleum ATF is more unstable and viscosity is effected more during cold to hot running temperatures.

Wear Protection
Assuming both oils have the same anit-wear additives the higher thermal stability of synthetic oil increases it's anti-wear performance compared to regular ATF.

Heat Dissipation
Heat transfer of both oils is similar but at high temperatures petroleum ATF breaks down and flashes to vapor or vapor/liquid combination causing heat transfer to greatly diminish. I've seen ATF when it's cooked and produces a gross popcorn smell!

Hydraulics
Heat dissipation as noted above is an important factor when it comes to shifting. If an oil cannot handle the heat and accumulates vapor (which compresses easily) then trans shifting efficiency will be greatly reduced.

Anti-Foaming
Anti-foaming additives also are an important point to add to this list ....since foam contains air shifting will be hindered. From what I found out both oils have similar quality levels of anti foaming agents.

In Conclusion
These are important factors to consider and in my view... go with synthetic oil. The reduced maintenance offsets the cost of the oil. We change the oil and filters every 3 years compared to every 40,000 KM before synthetic.

The zero failure rate within our fleet is phenomenal and looking at the cost of a Reman Allison transmission you could buy truckloads of synthetic oil.

Please share this post and leave your comments below if you have any experiences yourself or just want to add to my information :)

Allison Automatic Transmission Retrieving Codes

2012-06-04T20:30:00.000-07:00

The Allison Automatic Electronic Transmission offers a quick method to retrieve trans codes without requiring the Pro-Link reader. This is for older models before Allison required shops to have the DOC software to have any hope finding out what the fault is.

The video above is all about a preset code which in this case is losing the "output speed sensor" signal to the Trans ECU. I unplugged the sensor connector and once you try to move forward the transmission defaults into 1st gear. Without an output speed signal the ECU does not know where the transmission output speed is at... so it goes into this mode to protect the transmission because of the programming set up by Allison.

The output speed sensor can be checked out with an ohm meter which averages around 350 ohms depending on ambient temperature. Of course the wiring and connections is a step that should not be ignored. Any kind of resistance in the 30 foot harness running to the driver's cab will give a false signal. Opens and shorts are possible as well since the wiring is exposed to the environment. CHECK OUT THESE PREVIOUS POSTS ON THE ALLISON 3000 SERIES AUTOMATIC TRANSMISSION

Ford 6.0 Liter Diesel Engine Miss When Hot

2012-05-18T23:47:00.000-07:00

I have a question for all you Ford Diesel Mechanics Our fleet has a 2004 F550 with the 6.0 Liter and it developed a miss when hot. I test drove it for 1/2 an hour without the trailer and Bobcat and it took that much time for it to start missing. It comes on suddenly like someone hit a switch. Before that it ran perfectly with tons of jam. It also smoothes out at 2000 rpm.

All the injectors have been replaced along with the EGR. The injection pressure is down 10 psi and I was informed that a low pressure will take out the injectors again eventually. I would love to hear from any mechanics or owners who have come across a similar symptom. Please leave your comment below...much appreciated!

Mechanic School Bus Pusher Model Overview

2012-04-30T11:59:00.000-07:00

Mechanic Notes: working on school bus pushers.
The Bus Mechanic has a different approach compared to working on a pusher school bus since the drive train is reversed at the back end. The controls are hard wired to a major junction box in the rear engine compartment. They have a single drive axle (1998 model pictured here) with a stubby driveshaft which eliminates a 30 foot driveline. That's one advantage to this design along with a very low noise level for the operator.

Since all the weight is on the rear axle another obvious advantage is the great traction and handling, especially in the winter. The multiple leaf spring pack provides a solid ride but without the hard knocks of a forward chassis model. Having one drive axle compared to a Class 8 tandem makes life easier when it comes to axle work. With just one axle the brake shoes are a special size at 8 5/8 inch wide with 16 1/2 inch brake drums.

The rear engine design has it's pros and cons. The front end is a real treat to work on as you can see here. however you need to lay over the top of the engine for valve sets or head removal. The transverse fan is common in ER models which use a hydraulic drive fan motor but in this MVP Thomas pusher with a CAT 3126 the fan drive is belt driven.

As a Mechanic you will have new and exciting challenges in whatever piece of equipment you work on and in time you will always find easier ways to work around problems and get to know the symptoms / solutions as time goes on.

A Mechanic On Mechanics

2012-04-26T23:38:00.003-07:00

My Mechanic's Thoughts On The Field Of Mechanics
I never thought that I'd be sitting here blogging about the mechanic's trade 35 years after getting into a Heavy Duty Mechanic Pre-Apprenticeship Course. Back then Heavy Duty Mechanics was an all around trade which involved all heavy equipment including class eight trucks, earth moving equipment and automotive vehicles.

Years later Commercial Transport serving the transport truck field came on board and HD Mechanics became an earth moving / Mining equipment trade. It was information overload back then with all this equipment combined into a 6 month course. No complaints, it was a welcome handful of knowledge.

Realistically you wouldn't be able to hop around from a truck shop to a Mining site too easily because of the diversity in each industry. working on a P&H shovel is totally different compared to a Class 8 highway truck. I worked for Highland Valley Copper in Logan Lake for a few months (between jobs) and it was policy for new mechanics to start with the Shovel and Drill crew. I had copper mining experience during my apprenticeship but I felt like a newborn climbing up a drill mast on a graveyard shift.

The Mechanic trade is full of new experiences and I have stories I can tell, some are strange and quirky. For example:The GM diesel engine that ran backwards one day and the heat riser valve that trickled down to block the muffler causing grief and embarrassment (ate some hours on that one). But.....If you are human you WILL error.

I had a very nasty Journeyman during my second year apprenticeship and he had minimal time to teach me anything and thought apprentices were a waste of skin. Unfortunate but luckily he was the only low point of my career and until I became certified I had the pleasure of working with very honorable Journeyman.

I couldn't wait to become a Journeyman and teach others, it's rewarding to help others. You look at rich and powerful people who are avid philanthropists who state that giving back is the most satisfying gesture of all. It doesn't have to be cash or cars but sharing your knowledge is priceless.

I still remember things I was taught that are still with me to this day so keep it in mind when someone asks you a question :)

Remember To Think Safety On The Job...Don't try this at home. These guys in the video below are testing out an air bag. After too many beers.....

School Transportation News

2012-04-25T09:30:00.001-07:00

School Transportation News - Overview

In my opinion School Transportation News is the most up to date school transportation magazine that's available both online and offline. They publish 11 months out of the year and clearly have their finger on the pulse of the school bus transportation industry.

They are a great source for what's happening in the industry along with trends that affect the safety and efficiency of school bus transportation throughout North America. School Transportation News is viewed by over 23,000 people working in the industry along with agencies from all levels of government and national associations.

STN is always looking for the latest news and stories related to school bus transportation to keep the magazine current. Below are some highlights that I recommend from their website.

They have a Resources Page with maintenance tips, repairs and specifications.

Hundreds of articles: My personal favorite the School Bus Bay section.

Also a social media section called STN SOCIAL where school bus mechanics and anyone interested can hang out, interact, ask questions and publish new found solutions to a problem.

Since School Transportation News comes in a Digital Version you have online access to everything and anything school bus related. I recommend taking some time to check it out!

Cat 3126 Hard Starting & Running Rough

2012-04-24T12:10:00.000-07:00

The CAT 3126 Diesel Engine uses electronic fuel injection and they use HEUI (Hydraulically actuated, Electronically controlled Unit Injector) which require high pressure engine oil to actuate injection. The high pressure oil pump is mounted on the driver side and is engine driven. The hard part of this problem regarding our fleet is we do not have any CAT 3126 software to troubleshoot this problem.

So as with DT466 electronic engines the most common failures is the o-ring seals on the injectors. If high pressure oil is bypassing, the injection cycle is incomplete and the hard start poor running condition develops.

Side Note: By varying the oil pressure, injection can be controlled independently of the position or speed of the engine crankshaft or camshaft. The injectors are controlled by a Powertrain Control Module or PCM. Injection Pressures can reach as high as 18,000 to 24,000 PSI.

Since this particular engine has accumulated lots of miles without having a major tune-up besides a valve set we pulled all of the injectors and found the problem. The o-rings failed on a couple of the injectors enough to cause a constant problem every day cranking over the engine excessively to get it started and having a bad miss when warm.

Cat Engines specify that you need a Cat tool specifically designed to install these injectors, well since we only have a few of these engines in our fleet (and want to save money on tools) we found another way to push the injectors into the bore.

Use an appropriate sized combination wrench to gain leverage using the open end, coat the o-rings with clean engine oil and seat the injector using the injector hold down or body casting. (whatever you use take care and push the injector into the bore without force making sure it goes into the bore evenly). using the hold down bolt to install the injector is not advised but you can lightly snug it up as you progress.

The main point here is to not pry on the very top of the injector where the solenoid is located.We found this technique in our International installation manual. The HEUI injectors are used in their engines as well.

I hope this information helps you out the next time you have a CAT 3126 Diesel Engine with a hard start or rough run condition.

Cummins 5.9 Diesel Fuel in Oil

2012-04-23T07:31:00.000-07:00

Replacing Injectors Cummins 5.9 Diesel Engine

Here is a question I received from one of my subscribers and since it's a common problem with the Cummins 5.9 diesel engines I wanted to post it and share it. This applies to the 2004.5 - 2007 year engines.

Question: I have been working on a cummins power generator engine Model 6 BT 5.9 G1 for some time now. The problem was with fuel leaking into the oil sump. I was gonna over haul the engine but prior to that i would like you to suggest the problems related to this. Can you please advice me on the common problems which will cause the fuel to leak into the engine sump.

Answer: Leaking injectors is the most common problem with a fuel collecting in the oil pan. If you're finding your oil level is rising this may be the problem. I usually put new fuel connecting tubes with new injectors (the Mechanic in the video calls them feed tubes). The feed tubes are indexed so you can't go wrong when lining them up with the injectors during installation. The Mechanic in the video explains in detail and makes this operation a snap.

This second video is from another Mechanic who demonstrates some important techniques when removing and installing Cummins 5.9 injectors. I love these videos because of the no frills production from technicians who have a good foothold and knowledge with this type of repair. NOTE: Torquing everything demonstrated here to specs is extremely important.

NOTE: Here's a post with a link to a 15 page manual on tools required, procedures and torque specs compliments of a Dodge Diesel Forum member. Thanks Boys!

How To Become A Professional Automotive Technician

2012-04-22T21:40:00.001-07:00

Professional Automotive Technician Advice.... from Eric The Car Guy.

Listen to Eric explain important details on becoming an Auto Technician including ASE certification. He speaks very candidly and fills in all the answers that you're looking for. The main point he makes is "go to a tech school!". I like his statement on finding a shop that will provide upgrading and help you advance in the trade. Check out the video if you're thinking about the automotive technician trade or ready to go full throttle, you'll find some great insight from an experienced mechanic who has been through it already.

How Diesel Engine Turbochargers Work

2012-04-20T08:25:00.000-07:00

How Diesel Engine Turbochargers Work

Mechanic Notes: A diesel engine is 'dead in the water' without the turbocharger. High pressure atomized diesel injection needs maximum air intake boost to operate efficiently. You'll know when the turbo is not working up to speed, the smoke show out the tail pipe will be the obvious sign.

Mechanic Checks for A Turbocharger Problem
If you suspect a turbocharger problem and the diesel engine you're working on is a mechanical model you can check the boost pressure which should be around 20 p.s.i.

Take the reading off of the intake manifold with the engine at full throttle and full load. Hook up a line and go for a road test and make sure you get a nice heavy pull on the engine. The next step is to remove the intake side of the turbo (easier than the exhaust side) and check the compressor wheel and shaft for any movement and wear or signs of engine oil in the piping.

The air induction system includes the air filter and piping which must not be overlooked. Simple steps include checking for a restriction in the air filter and visually checking out the piping for loose clamps and perforations. The first sign of a hole in the piping or a loose clamp will be a high pitched whistle, not to be confused with the characteristic whine that comes from a turbocharger under load.

This is a common problem and can be checked by setting the park brake (set wheel chocks as an extra precaution), foot brake on, transmission in gear and throttling up the engine RPM enough to feel a load. You'll need assistance with this test so you can look and feel for leaks.

Electronically controlled diesel engines will most likely flash a trouble code on the dash which requires diagnosis with a laptop / software. The modern day Mechanic needs software and a laptop...if you don't have these tools you're going to go down fighting.

Here's an excellent video tutorial on how the turbocharger works. Check it out!

Cummins 24 Valve Turbo Diesel Torquing Head bolts

2012-04-19T22:57:00.002-07:00

Torquing Head Bolts on a Cummins 24 Valve Turbo Diesel Engine.
This is a video I posted years ago on Youtube. There was a lot of noise in the background and I just grabbed my torque wrench and went through the sequence. I apologize for the poor video quality but I get my point across :)

The Torque Pattern
Start from the middle of the head in a circular pattern outwards. Torque to 59 ft.lbs then 77 ft. lbs. check again at 77 ft.lbs. then finally another 90 degrees. Coat threads lightly with engine oil. This is a universal torque pattern that makes sense to apply to any type of diesel or gas engine.

Starting from the middle and moving outwards so the head is fastened down evenly. Cummins uses a system called torque and turn which accounts for the extra 90 degrees to finish off. The Cummins 24 valve turbo diesel (5.9 Liter or 359 cubic inches) is one of the most dependable engines in our fleet.

I must add that this diesel is an electronic model known as the ISB which stands for Interact System B.

Below are some extra Specs:
- Fuel System = Direct Injection
- 1998.5 - 2002: Electronically controlled Bosch VP44 rotary injection pump.
- 2003-2007: Bosch high pressure common rail injection.
- 235 - 325 HP @ 2,900 RPM
- 460 - 610 lb-ft @ 1,600 RPM

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Mechanic Careers And How You Can Succeed

2012-04-18T22:50:00.001-07:00

Mechanic Careers - How to Succeed & Decide If It's Right For Your Future.

Yes it's true that Mechanic Careers are abundant around the world but getting started is the hard part. You may have a background in the trade which is a bonus. You need to be good with tools and have a certain level of aptitude that gives you the upper hand when assessing each job you receive. Taking a pre-apprenticeship course is a wise investment.

There are thousands of colleges and technical institutes that offer 6 to 10 month courses. The main focus is to learn the basics, why? If you are interviewing with a prospective employer they will smell a rookie from a mile away. Not knowing basic terms and technological lingo will prevent you from selling yourself.

A Mechanic pre-apprenticeship course instructs you on everything from nuts and bolts to tools and the all important theory you need to become confident when you apply for a job.

Successful Mechanics Possess A Great Attitude Attitude Attitude

I've worked with fellow Mechanics (not many) that had bad attitudes. The terms "good enough" or "let's just patch it up and kick it out the door". Your signature needs to be on every job you do. Working in retail will subject you to different personalities.

If you show that you care even the nastiest customer will bow to your compassion and understanding. Think about it...would you rather spend money on a kick butt vacation or pay $400.00 on a fuel pump on your 10 year old car that's ready for a trade-in?

Most people aren't in the best of moods when they have to open up their wallet. That's why I say attitude is a huge factor when an employer is ready to hire. I believe it's much easier to train someone with a positive attitude compared to the opposite mindset.

Mechanic Careers - My Big Break!

To Succeed with a Mechanic Career all you need is knowledge and the right mindset to catch an employer's eye. The more you apply the odds get better, don't limit yourself to your hometown. I went north as a young man (sounds familiar?) as a total greenhorn.

With a 6 month pre-app and maybe a year of experience in mining I pulled up anchor and worked up North, a 12 hour drive and if I had not taken the challenge to work in a customer truck shop my Mechanic Career would have been extremely limited.

So go for it! get schooled, get out of your comfort zone.... be ready to uproot yourself and start your career with a passion!!

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DT 466 Fuel Inlet Restriction Test

2012-04-16T16:50:00.001-07:00

DT 466 Diesel Engine Fuel Inlet Restriction Test - Robert Bosch MW / A injection pumps.

Another DT 466 engine diagnostic test procedure that you can carry out easily is a fuel inlet restriction test. This will tell you if you have a restriction between the fuel tank and the suction side of the pump.

The causes of a restriction may be a kinked or pinched fuel line or a blockage in the fuel suction line in the tank. The tools required is a tee fitting and a vacuum guage with a 0-15 In. Hg. between the outlet of the Primary fuel filter and the suction side of the injection pump transfer pump.

DT 466 Fuel Restriction Test Procedure

Run the engine at high idle no load and measure the restriction. If it exceeds 6 in. hg. there is an excessive restriction and it has to be located and repaired. most times the fuel line can be at fault or something foreign entered the fuel tank blocking fuel flow.

The mechanical DT 466 diesel engine may be long in the tooth now but for an owner / operator / Mechanic who is handy with a wrench these models are easy to work on.

If you're wondering what diesel engine I would recommend for P&D, farming, construction whatever....the International DT 466 is golden in my book.