~~~~~School Bus Mechanic

Diesel Mechanic Jobs Advice

2012-01-21T22:27:00.000-08:00

Diesel Mechanic Jobs - Is This Career Right For You?

Diesel Mechanic Jobs

Diesel Mechanic Jobs - Choosing Your Career Path.

Looking back 35 years if I had not gone to the local apprenticeship counselor for advice my career path might have been different. Looking at Diesel Mechanic jobs was the furthest thing from my mind at that time. In high school I enjoyed metalwork class and working with my hands. The tricks I learned on the metal lathe amazed me. Making a bench vise from nothing was a huge task, cutting threads on the lathe and using a foundry to cast the vise from aluminum was addictive and rewarding.

So after high school it was off to the apprenticeship board office to inquire about becoming a Machinist. The counselor advised me that quote: "you don't want to become a machinist, you'll be standing at a drill press 8 hours a day"..."Heavy Duty Mechanics is the trade of the future". I remember those words well and took them to heart. Diesel Mechanic jobs were plentiful back in the seventies and they still are today!

I am not disrespecting the Machinist trade in any way. Working in the mine industry they were the backbone of the shop with a smelter and mill to maintain. It amazes me what they can make out of a cold roll piece of metal. Our present shop has a metal lathe so I can still get that machinist feeling once in a while :)

Diesel Mechanic Jobs - Assessing Your Desire and Abilities

If you're seriously looking for a career as a Diesel Mechanic

I would ask yourself these 10 Questions....

1. Do I like to work with my hands?
2. Can I handle working around grease and oil?
3. Can I handle making mistakes and be OK with that while turning it into a learning experience?
4. Is a lower wage to start with tolerable with my present lifestyle?
5. Can I work with other Mechanics & compromise when deciding on the best way to fix a problem?
6. Am I willing to re-locate to get started in this trade?
7. Will I project a positive attitude every day and not be defeated by frustration?
8. Am I willing to take on diesel mechanic jobs that challenge me?
9. Will I be respectful of my workspace and fellow work mates?
10. Will I continue to improve myself, learn more about new technology and share everything I know with new Mechanics starting out in the trade?

If you can nod your head to most of these points I can tell you it's time to get motivated and sign up at your local technical training institute. You don't have to be a crackerjack Mechanic to make it in this profession. I look for positive attitude first, along with desire before even considering someone for a job. The technical stuff can be taught but a positive mindset is something you either acquire or have already inside you.

If you are not sure about looking into diesel mechanic jobs as a career then I would recommend clicking the link below to do an assessment on what would be the best for you. You need to be passionate about what you want, once you find your place getting out of bed every morning will always be easy :)

I have no regrets about the career choice I made. Eventually becoming a supervisor and directing a crew of mechanics in a fleet shop is challenging and rewarding at the same time. Everyday is different with new challenges around every corner always learning something new which is never boring. If you choose to look at diesel mechanic jobs as a career I wish you the best and great success!!

For Career Test and Career Counseling > Click Here.

Recommended Resource: Diesel Mechanic Jobs

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International Diesel Engine DT466 Fuel Rate Adjustment

2012-01-20T22:11:00.000-08:00

International Diesel Engine DT 466

The International Diesel Engine DT466 fuel rate adjustment is easier on this model because it has a mechanical injection pump.

How to adjust fuel rate (turn up the pump)on the popular Med Duty diesels. Roughly covers 84-92s.

You use a 3/8 socket and 10 mm allen head socket down the top plug hole. The jam nut once loosened allows you to back off the allen head screw. It has to be adjusted counterclockwise without causing too much smoke. Go back and readjust as required to reduce exhaust smoke or adjust the starwheel as explained in this video one way or the other to control smoke from the pipe.

This International Diesel Engine is all mechanical suited for the handy mechanic who likes to work on his own equipment. There is nothing fancy about these engines which suits a lot of people in the industry. That is why this international diesel engine is so popular.

The Turbo Encabulator

2012-01-02T12:22:00.000-08:00

The Mechanical background behind the Turbo Encabulator: Rockwell International decided to get into the heavy duty automatic transmission business. They were getting ready to tape their first introductory video. As a warm up, the company rep who was acting as the presenter, began what has become a legend within the training industry. In fact, he should have won an academy award for his stellar performance rattling off the non-existent mechanic terms.

Now remember to keep in mind, this is strictly off the cuff, the turbo encabulator information has not been written down. Nothing he says is actually true. He had NO script! The mechanic lingo here doesn't make sense but sounds familiar. I use as a joke the terms 'filber flange' and 'grapple grommet' when explaining a problem to catch someone off guard.

This was simply meant as a rehearsal for the camera, lighting and stage crew to check their equipment. So it's all total meaningless drivel that he made up as he goes along, right off the top of his head. The Turbo Encabulator just might work out... :)

I found 2 different mechanic terms 'entabulator' and 'encabulator' since the latter was found more frequently online I stuck with that one. Not that it's crucial to be exact with the term :)

Note: Thanks to newsletter subscriber Tristan for sending me the video.

MaxxForce DT Diesel Engine

2011-12-16T16:49:00.000-08:00

This video is on the big Bore Models in Highway Trucks and covers a large part on how the MaxxForce Engines are contructed.

The MaxxForce DT Diesel Engine is the newest edition of the original DT 466 and DT 466E diesel engines. Our fleet brought in five 2010 IC conventional school buses with this engine model. They are 230 HP with a 7.6 Liter (466 cu. in.) displacement.

They stuck with the wet sleeve cylinder design which is very popular with us Mechanics who do in-frames. If you've ever done an in-frame there is no comparison to an integral (DRY) cylinder diesel engine model. The dry sleeve design of course means pulling the entire engine out of the frame. This adds labor and parts expenses.

I did some research on these diesel engine models since it's always an advantage to know the details on our fleet engines. They have the roller cam followers which helps reduce wear and tear on the camshaft and valve train. A 4 valve per cylinder configuration helps with breathing and emission controls.

This video explains the EGR system in Maxxforce 2010 Engine Models.

Other features include:

replaceable valve seats and guides
top of engine access to fuel filter and fuel/water seperator
top loading fuel strainer
maintenance free closed crankcase ventilation system
internal cylinder dosing eliminates downstream fuel injection equipment.
On-board diagnostics system
International's electro-hydraulic generation two (G2) electronic controls for optimizing fuel economy and delivery.
G2 fuel system allows diesel particulate regeneration without equipment dowstream.
EVRT electronically controlled turbo creates improved engine torque curve and response and produces exhaust back pressure to better control EGR rate of flow and exhaust braking.

Jacobs exhaust brake (optional) up to 150 brake horse power. Works with the EVRT Turbo eliminating standard exhaust brake system. The MaxxForce DT Diesel Engines in our fleet have been running great so far.

Mechanic Checks For Winter Operation

2011-11-29T22:04:00.000-08:00

A Mechanic has to maintain vehicles accordingly depending on the conditions and adapt throughout the seasons which includes hot and cold weather. Since Winter is now upon us it's time to cover some preventive maintenance tips that experienced Mechanics are familiar with, but I want to share the basics with everybody.
Coolant Testing the coolant is of course very important and changing the coolant and thermostats should also be considered. Cummins promotes DCA (dry chemical additive) checks, to make sure the system is not overcharged or undercharged. DCA prevents liner pitting by reducing air bubbles forming in the cooling jackets. Changing the coolant (non lifetime brands) with the thermostats every 2-3 years isn't a bad idea since coolant eventually breaks down and the acidic build up that forms starts to eat up gaskets and castings.
Belts and Hoses who doesn't know the importance of these bad boys. They get the most abuse from constant tension, heat produced from driving the belts and hot/cold temperatures on the hoses. I always say "when in doubt change it out". Pulley bearings and belt tensioners need to be checked out and the cooling system should be pressure tested. School buses have 1 inch cooling lines throughout the bus interior and need to be observed for leaks and loose clamps.
Batteries batteries can either be load tested once a year preferably in the fall or changed when needed. Sometimes the latter happens at the most inconvenient time when it's cold, wind blowing ....a spare bus (in my case) needs to be fired up from a cold condition. So we generally do the yearly load test and go from there deciding what step to take next.
Block Heaters Most buses in our fleet have the conventional block heater system. Our plug-ins are timed in cycles to come on during certain ambient temperatures. We test them at every service to stay on top of 'no start' conditions in the cold. A couple dozen of our newer buses have diesel heaters that have timers so they come on a couple of hours before the run.
Tune Ups Mechanics know the advantage of keeping an engine tuned up. Easier starts less fuel burned is the main objective. Valve sets, fuel filters and air filters are all you can really do to a diesel engine especially with newer models. Checking for engine codes doesn't hurt, some codes do not light up on the dash and become inactive. Common sense helps in this area of maintenance and needs to be applied looking at everything that makes a highway vehicle function. The regular Mechanic or the 'Mechanic in you' can figure this stuff out.

Diesel Mechanic's Favorite Diesel Engine

2011-10-31T23:40:00.001-07:00

This a rather boring video but just listen to that diesel engine purr! Sit back with your favorite beverage and enjoy... The Cummins C Diesel engine 250 HP running in one of our pusher school buses (early nineties model). This engine is one of my favorites in the fleet, one reason is it's mechanical fuel injection. For the Mechanic... much easier to work on compared to today's units.

I had one of the Mechanics from the Cummins dealership ask me if any of our buses with this engine model were coming due for auction, he was interested in picking one up because of the non-electronic fuel injection system. These are popular models mainly because of the basic mechanics involved when working on them. The Bosch fuel injection pump is straight forward and works off a mechanical linkage operated by an air throttle pedal. The fuel shutdown is controlled by relays and is a very basic hard wired electrical system.

I know I'm dating myself here but electronics just needs a wisp of condensation and you're going to end up with some trouble. The precise technology of today is amazing stuff and controlling operating systems with printed circuits can't be beat compared to older technology but I sure miss it. Let's just say for all of us modern Mechanics you've got to stay sharp!

A Diesel Mechanic Career Requires The Right Training

2011-10-29T13:48:00.001-07:00

If I was looking for Diesel Mechanic training I would check out the school featured in the video below. Becoming a Diesel Mechanic these days is not easy as it was 20 or 30 years ago. All the engines were mechanical injection and a lot easier to work on and diagnose. If you had an engine miss all you had to do was crack a fuel injection line one at a time to track down the bad hole and drip diesel fuel onto the ground. But now since new emission standards totally transformed the diesel engine industry it also changed the way a Diesel Mechanic thinks.

Now you HAVE to use software to properly troubleshoot an electronic diesel engine. You're dead in the water without the right tooling. If I get a question here about an electronic diesel engine with a code, the first thing I suggest is hook up your laptop and if you don't have one with the engine manufacturer's software take it to a shop that does. It's the way of the future now with sensors monitoring every output and input imaginable to help the Engine computer to keep the emissions down to a safe level.

I totally agree with this path industry is taking even if finding an engine code problem can be a frustrating task. If you're someone who has tinkered with mechanics for a long time you or just got a taste of it in your high school automotive shop you're ready to upgrade. Mechanic College is your best step, on the video below there are reps from Cummins who take students from this course and give them a job and that turns into a career.

There are so many opportunities out there in different industries for diesel mechanics all you have to do is go find them. You most likely would have to relocate (I went up North during my 2nd year apprenticeship) to get the job you want. You also have to show enthusiasm to your potential employer. Tell them you want to learn and grow with their company. If you enjoy the Diesel Mechanic trade and want to succeed... attitude and training will get you there in no time.

The New Airless Tire From Michelin

2011-10-24T10:14:00.000-07:00

This is a new radical design from Michelin (they call it the twheel ..not sure if that's the proper spelling). Mechanics beware, someday the tire machine will become extinct. these tires have a sheer band, deformable wheel and flexible spokes.The one downer about them is law enforcement spike strips will not stop them. Flat tires will be non-existent with this technology. The price? If they are guaranteed for life then I might shell out some serious cash for a set. Looking at the photo they appear to flex quite a bit so the ride should not be compromised although maybe a different feel on the road.

Here's a quick video from Michelin. They say it's going to be another 10 to 15 years away before we'll see it on the market. This would eventually take work away from the everyday mechanic but that's progress.

Blue Bird School Bus - A Brief History

2011-10-22T15:43:00.000-07:00

This is a quick post on the history of Blue Bird School Buses followed by a very cool video below. It all started in Fort Valley, Georgia, 25 miles south of Macon. A man by the name of Albert L. Luce, Sr. was a Ford auto dealer who built a school bus for one of his customers which was comprised mostly of wood.

The bus was built on a Model T frame and Luce was not totally happy with the quality of his prototype. He was encouraged to build another one of higher quality. He followed through and completed it in 1927 with a steel body, much more durable than the wooden design.

He sold it to a customer in a nearby town who needed it to transport school children. He built 7 more buses and eventually sold his Ford dealership and founded the Blue Bird Bus Company.

Check out this great video on the history of Blue Bird Buses. as told by Albert L. Luce, Jr.

Prevost Coach Motor Home - Guided Tour

2011-10-17T23:39:00.000-07:00

My friend Tristan who is also a member of my newsletter was passing through town and invited me to come and have a look at his 1995 Prevost Coach. I took some snapshots so I could share them here and show everyone how much quality goes into these units. Marathon Coach Inc. is a bus conversion company that turns the Prevost into a high end motorhome. After taking the tour I was very impressed with the quality that goes into these rigs. His car is out of site being towed on a trailer. He mentioned that parking is limited with a bus this size so he has to plan ahead for each destination carefully plotting out an accessible route.

The hot and cold water system is all stainless and obviously plumbed by a professional. It doesn't look like a 16 year old coach with absolutely no indication of any corrosion. The Marathon Coach factory must have very well trained employees and/or licensed tradesman working for them.

The Diesel Engine is a 500 Horespower Detroit Series 60. The air bag you see here at the fan drive pulley on the left adjusts the belt tension automatically. I'm thinking the fan drive is actuated only when needed saving horespower and wear. I've never seen this set up before which made it obvious that these bus manufacturers put a lot of thought into the design and installation of the components. Everything is very accessible and Mechanic friendly.

This alternator puts out a maximum of 270 Amps. I didn't take enough notes and can't tell you the model of this unit (maybe a Delco?), but I can tell you that it's a workhorse and is oil lubricated for good reason. I can't imagine how much heat this alternator develops keeping up to the demands of the DC system.

Have you ever seen wiring prettier than this? (CLICK PHOTO TO ENLARGE) It's open and laid out with easy access in front of the steering axle. The routing is nicely done and makes wire tracing a breeze. I could not find any signs of corrosion anywhere. The steering box below is easy to get to along with the transmission vehicle interface module. Usually you have to stand on your head to gain access to these components. Speaking of transmissions this rig has an Allison New World 4000 Series automatic transmission. We're talking heavy duty drive train and axles to support the big load of the Prevost.

This is the rear electrical panel in the engine compartment similar to the front end panel. Troubleshooting is much easier with this kind of layout. The terminals are all easily accessible and the wiring schematics are attached to the access doors. I would be very surprised if there were any shorts or open circuits with this bus after looking at the wire routing and the quality of the circuit board installations.

Last but not least is the manuals that came with the bus. Tristan has them neatly stored in this cargo bay along with his tools next door. He's a licensed Mechanic and does all his own repairs saving a heap of money in the process. Without manuals a Mechanic is shooting in the dark especially with the variety of technical systems to be dealt with on this bus.

School Bus Heaters Article

2011-10-08T23:00:00.000-07:00

I recently wrote an article for School Transportation News Magazine on Bus Heaters. The nice thing about researching for this subject is I learned a lot of new Mechanic information on the subject. Since our fleet has over 2 dozen bus heaters it was a topic of interest. Here is the link that will take you to the online digital version.
The pre-heating capabilities from these little heaters are phenomenal. There was a lot of positive feedback from fleet operators who saved fuel reduced engine wear and harmful emissions from cold diesel engine start ups. They don't cost a lot to run and can be adapted to bio-fuel and gasoline. The heat ratings go as high as 45,000 BTUs. One thing to point out especially with school buses is the safety and comfort of the kids these heaters provide. Imagine a bus breaking down on the highway during frigid temperatures. These heaters would be a huge asset to have around for that purpose along with defrosting the windows much quicker solving another common safety issue.

Here's a great video on an Espar coolant heater installed on a boat. The install here is the same for any kind of application.

Cummins N14 Injector Troubleshooting

2011-09-28T22:34:00.000-07:00

I found this interesting video from a Mechanic named Daniel who posted an in-depth video on troubleshooting and repairing an injector miss problem on a Cummins N14 injector. This is an electronic diesel model that has solenoid controlled injectors pulsed by the engine ECM. It's an interesting video and very detailed for the aspiring Cummins N14 Mechanic.

Cummins N14 Injector Troubleshooting and Repair "With this particular injector the way it works is that the solenoid is in an always open position allowing fuel from the rail into the injector and only closes during the downward stroke of the metering plunger so as not to allow the fuel to go back to the rail, rather trapping it in the injector and metering it to the cylinder. Technically, with this particular injector it would be more that the injector fuel supply is “closed” electronically at the injector. danielresume 6 months ago The solenoid is the only aspect of this injector that is electronic and governed by the ECM. It has been my experience that when these solenoids get weak or fail completely the engine might still run at idle without a misfire but under power will miss and have no power. The injector also has a ceramic check ball and metering plunger which will cause the same condition under power if worn as they will allow fuel to escape under pressure rather than injecting to the cylinder." I hope this Mechanic tip has been helpful.

Mechanic Tips-School Bus Fleet Preventive Maintenance

2011-09-20T22:55:00.000-07:00

Every Fleet Mechanic will have there own ideas on how to set up the best PM program for their equipment which will vary for different locations. With different climates, road conditions and power trains the procedures will never be exactly the same. Our shop likes to condense the annual PM since the regular checks are carried out every 5000 Kilometers (3000 Miles). Oil changes are done every 15,000 Km with an oil sample to be analyzed. Fuel filters are replaced at every oil change.

The Allison 2000 and 3000 Transmissions are all running on TES-295 Synthetic oil which has drastically cut down on repairs. Right now we change the oil every 3 years, the newer buses have prognostics which tells us with a dash light indicator when the filter and oil needs to be changed. Air filters are replaced every year regardless of the mileage. Steering Filters are serviced along with changing the oil every 2 years. Valve Sets are carried out according to the Manufacturer i.e Cummins every 5000 Hours or 240,000 Km (Electronic Models). With the introduction to emission controls in 2007 we now have to perform manual regens if required and replace the DPF (diesel particulate filter) every 150,000 Km (90,000 Miles)

Air Dryers every 2 years with a new unloader kit and dessicant filter. Dirt is a factor on school buses so we service interior heater filters and the entire lighting system (Non-LED lights). We check the starting and charging systems including the battery pack. If necessary we will run tests on the batteries and alternator. years ago alternators and starters were removed for rebuild but the time and parts did not add up as an economic strategy so we decided to give these components a 5 year life span before determining if they would need replacement. The cost has come down so much on electrical reman units, it's feasible to go this route with the added bonus of a warranty period.

Spring brake chambers are replaced every 5 years regardless of mileage and condition. The Mercedes MBE 900 requires a coolant and thermostat change every 2 years, the other diesel engines in our fleet do not have a time or mileage limit but we're working on that to prevent antifreeze deterioration and thermostat failures. Our tires tread depth is measured every Summer and pressures checked during each service.

Common sense plays a role with any preventive maintenance program and we found the best way to set one up is to sit all the Mechanics down in one room and go through the fleet figuring out the best program to cover all the bases. Breakdowns will quickly eat up your labor time and parts budget like wildfire so keeping on top of maintenance with a feasible program will pay you back 10 times over.

International DT 466E In-Frame Repair

2011-09-11T23:19:00.000-07:00

The International diesel engine project is at the head installation stage. We had the head sent to a machine shop and inspected. The valves were touched up and the head was checked for cracks since the failure was an overheating condition. If you're going through all this work it makes sense to take every step necessary to prevent a come-back.

With the head installed the injectors come next. They are hydraulic electronic unit injectors that run on high pressure oil controlled by the electrical signals from the engine ECU. The valve rocker arms are then torqued down and the valves are set at .025 inches.One thing to note with DT 466E engines is the diesel mechanic needs to make sure the engine oil pressure is up to specs because it is responsible for engine starting. If you have low oil pressure for whatever reason you will experience a hard starting or no start condition. We have since returned this bus into service and it's running nicely. The total cost of the in-frame was much less a complete rebuild on a non wet cylinder diesel engine. The fact that everything can be performed in-frame saves a LOT of time and money. One of the disadvantages of running an engine with removable cylinders is they are not part of the block and can move against the sealing o-rings around the liners. If a Mechanic has to rebuild a DT 466 diesel engine once in it's lifetime after hundreds of thousands of miles, I would say that engine definitely paid for itself.

International Diesel Engine Rebuild Installing Liners

2011-08-04T08:22:00.000-07:00

In the past International DT466 Diesel Engines used 2 orings to seal the liner in the block. Here is the upgrade with the one seal. You notice we're using Lubriplate grease to pre-lube the seal. You can also use cooking oil which International recommends, all the Mechanics (myself included) in our shop swear by Lubriplate and it has never failed us.

Installing the liner is the next step.It's recommended to keep the liner seated firmly after installation as pictured here with metric fasteners and washers. The liner protrusion has to be checked as well to maintain a good seal surface for the head gasket. I hope this quick Mechanic information tidbit helped you out.

International DT466 Diesel Engine Rebuild Cylinder Liner Seals

2011-06-25T08:20:00.000-07:00

International DT466 Diesel Engine Rebuild Update
The next step after removing the head is pulling out the pistons. Once the rod caps are removed they can be pushed up through the cylinder liner and out. Light tapping with a wood drift works as well. The cylinder numbers will be stamped on the connecting rod caps. If there was a thick build up of carbon at the top of the liner, that needs to be removed for the piston rings to pass by easily.

The liners are going to be replaced anyways so you don't need to be gentle removing them. You need a liner puller for this job because of the o-ring seals that have been press fit against the engine block for many years, they require a good pull to jar them loose. (for those of you who have never used a liner puller) The 2 short feet rest on top of the block while the long arms hook onto the bottom edge of the liner. A socket and wrench is used on the top nut and the liner is easily wound out of the block.

Having removable liners for the DT 466 E Diesel Engines makes the in-frame a very cost effective process. We paid around 1500.00 for the "Works Kit" from the International dealer. That's a cheap rebuild! There is no engine removal and that saves a ton of labor.

Once the liners are removed it's time to do the cleanup on the block deck and engine liner bores. While you're doing this keep an eye out for anything unusual like wear on the block surface or cracks in the casting etc. DT 466 Diesel Engines are bullet proof so the chances are slim to none there will be a problem.

Here's the bad liner or should I say the bad o-ring. We had a full crankcase of sludge, with a gravity feed from the block coolant supply. So the first thing to check if you are losing a lot of coolant is pull the dipstick and check for a sludge build up in the oil.

The new liners have been upgraded with only one o-ring compared to the original 2 seen here. This is the only disadvantage of running wet liners but this type of failure is not overly common, especially with this engine having under 100,000 miles.

If you are a Mechanic you want to make sure to check on recent Technical Service Bulletins on these DT Diesel Engines . We found one that brought our attention to the new style liner seal and to use a vegetable oil to lubricate the seals. They also need to have retention hold downs after installation to keep them seated in the block.

DT466 International Diesel Engine In-Frame

2011-06-04T20:51:00.000-07:00

After removing the radiator assembly from our International DT466 Diesel Engine and then the oil pan that was required to check for leaking liners, The next step is to remove the cylinder head. The head will be sent out for inspection at a local machine shop, the head will be put into a hot tank so all the fittings and plugs have to be removed . The machine shop will do a full service which includes a magniflux to check for any cracks and a valve / valve seat grind to true up everything back to new. The turbocharger will be rebuilt and injectors sent to a fuel injection shop for flushing and bench testing to check for proper operation. These are necessary steps for a Diesel Mechanic to ensure a healthy start up after assembly.

DT 466 International Diesel Engine In-Frame - Removing Radiator Assembly.

2011-05-23T13:27:00.000-07:00

The International DT 466E Diesel Engine that's running in a school bus is more accessible by first removing the hood as in the previous post. The Mechanic does not need to be standing on his head to dis-assemble everything.

The radiator assembly comes out as a unit. You can see from the photo these models have a split radiator and charge air cooler. You might think half of a normal radiator might cause a problem but we have not experienced anything major besides deterioration over time of the radiator core. Usually they cannot be repaired and a complete unit needs to be installed in case of any failure. This radiator had been replaced not too long ago so all a Mechanic has to do is remove the radiator and send it out to be flushed and checked at a radiator shop.

Thinking ahead is a good practice for any Mechanic performing a major overhaul like this one. The radiator, turbo, oil cooler, water pump, charge air cooler and cylinder head all needs to be inspected carefully right away and either sent out or repaired which ever is the most practical. Stand by for more Mechanic Information on our in-house DT 466 International Diesel Engine Rebuild.

DT 466 Diesel Engine In Frame Rebuild.

2011-05-16T06:56:00.000-07:00

One of our International DT466 diesel engines had an incident a few days ago. It over heated and shut down, after discovering coolant in the crankcase the only conclusion was to remove the oil pan and inspect it further. This is an electronic 2001 model but the mechanical principles still remain the same. They have wet liners which are sealed by o-rings keeping the coolant seperated from the crankcase.

After removing the oil pan and pressurizing the cooling system the problem was obvious. One liner had failed o-rings which caused the coolant leakage problem from the beginning. This will require an in-frame rebuild. I am going to document this procedure step by step so you can see the inner workings of the DT 466 Diesel Engine.

STN Going Social With Mechanic & School Bus Industry News

2011-05-09T08:40:00.000-07:00

School Transportion News has a new social network that covers everything imaginable in the school bus transportation industry. I especially enjoy the TechNet section which covers school bus repairs and new technology. This is a discussion group that anyone can join and participate in with questions and answers as well as comments.

With changing technology it's essential to keep in contact with other professionals in the field and share ideas and answers to challenges encountered on a regular basis.

Here's the link if you want to check it out. I highly recommend this site for up to date knowledge and a free ticket to rub elbows with an experienced group of school bus mechanics willing to share their knowledge.
http://www.stnonline.com/social

Diesel EngineTurbochargers Need TLC

2011-04-28T22:56:00.000-07:00

Cummins C Model Diesel Engine Turbocharger

The turbo on a diesel engine is an amazing piece of equipment that puts out thousands of rpms and gives us the boost we need to get into that perfect torque curve we need to power up a grade. You will know right away when the turbocharger is faulty. Without that charge air flowing into the intake the ratio between air and fuel will go south and heavy plumes of exhaust will pump out of your tail pipe getting some unexpected onlookers staring you down along with a huge loss of power.

This Holset Model pictured here comes with a waste gate (the round housing top left). A boost line is connected to a diaphragm and when the pressure hits a pre-calibrated level the excess boost pressure is exhausted out at around 20 psi or higher. The compressor wheel seen here as well is driven by the exhaust turbine wheel on the opposite side, so it's a self driven unit.

This is pure genius and gives the engine the extra air intake volume to keep up with the fuel injection system. Both the compressor and turbine wheels should be checked periodically for wear on the shaft and if there is any scuffing on the turbo housing caused the blades making contact. You don't want one of these guys blowing up and debris getting into the intake.

School Bus Engine Rebuild Video Cat 3116

2011-04-06T17:58:00.000-07:00

Here's a video I put together going through the steps to rebuilding and installing a Cat 3116 Diesel engine in a pusher school bus. It's a big job and you can see it happen in a matter of minutes. It's much easier to assemble the transmission to the engine and use the trans jack for support and hydraulic hoist on the front end.

The whole works rolls right into the frame. Thankfully Thomas Bus allows the rear end frame to be removed. The Cat 3116 is a fussy engine to set up and you MUST have the Cat tool kit. There is no way to set up the timing, synchronization & fuel setting without the kit.

The valve train is the only weak spot on these engines, when they get too hot (in this case) the exhaust valve let loose requiring the major repair including a new cylinder head. Too avoid this keep the engine temperature down and check valve adjustment every 30,000 to 40,000 km (18-24,000 Miles). Enjoy the video....Please Leave a Comment

School Bus Mechanic Pictures..Exclusive! by jelletse

Diesel Engine Overheating School Bus Pusher

2011-04-05T23:49:00.000-07:00

The diesel engine on a school bus pusher is a strange design with a transversely mounted radiator. Operators love these units because are very quiet (engine in the rear) with a stubby driveshaft. Low occurrences of driveline vibration and hearing yourself think is a bonus.

One thing that does cause problems is the hydraulic fan drive system that runs the engine cooling fan. The steering pump driven off the compressor runs the fan hydraulic motor as well. For those who find this confusing, the engine fan assy. is attached to the hydraulic motor shaft. Since the motor is driven by the steering pump it is labelled as a motor.

If you find you have stiff steering and the engine is overheating as well, you might want to look at the hydraulic steering pump. Check the hydraulic filter and magnet that resides inside the oil reservoir. If there is anything metallic then you're on the right track.

Older fan drives have a control manifold that has a electric solenoid that is triggered by an engine coolant temperature sensor. once the 200 degree (approx.) engine temperature is reached then the flow control opens the gates to full flow directed to the hydraulic fan drive motor. There is no need to worry about a fan belt on these rigs.

Newer pusher school buses have a 2 stage steering pump with sensors and manifold that controls the engine fan with a module bolted to the side of the frame. One stage of the hydraulic pump runs the steering and the other stage runs the engine fan. You also need the software to hookup to the fan control module to check out the entire system for proper flow and other parameters.

School buses have come a long way from the old belt drive and incredibly noisy gear box system that were popular in the early 90s. I think I've just dated myself, OK now you know I'm a child of the 60s... Hooray for Bob Dylan and the Chevy 283 cu. in. engine.

Cummins Diesel Engine Fuel Injection Pump Installation

2011-01-29T12:46:00.000-08:00

The Cummins Diesel [Engine Model 'C'] fuel injection pump has been repaired, but there are still a few steps to take.

TIMING FUEL INJECTION PUMP:
The fuel injection pump MUST be timed by removing threaded hex cap located on the throttle shaft side of the housing. Remove timing pin from access hole and rotate the pump by hand until the timing tooth inside pump housing lines up with the middle of the access hole.
Engage slotted timing pin as the picture above shows. Install threaded cap hand tight until after injection pump is installed. The injection pump is now in the proper timed position.

PRE-LUBE INJECTION PUMP:
When a repair has been made on these pumps they must be pre-lubed with engine oil. Remove top plug from the governor housing with an Allen wrench. This particular model requires .71 Litres [24 oz.] . Failure to do this could cause damage during start-up.

TIMING THE ENGINE:
The next step is to time the engine by rotating clockwise [viewed from the front] while pushing on timing pin until it engages into the camshaft gear. Engine is now properly timed, the fuel injection pump is ready to INSTALL.

After the 4 mounting bolts are tightened, torque accessory drive gear retaining nut to 106 in. lbs. then DISENGAGE BOTH TIMING PINS. The injection pump timing pin just pulls out, flips around and stays installed on the pump for next time. The engine timing pin just pulls back and stays put.

TORQUE DRIVE GEAR RETAINING NUT:
Now it's time for the final torque 144 ft. lbs. NOTE: torque specs will vary depending on the injection pump model. Now it probably makes sense to you why it's important to disengage both timing pins. They will sheer off very easily being made out of plastic and debris will get into the injection pump housing or engine timing gear housing.

BLEEDING THE FUEL INJECTION SYSTEM:
Once the lines, linkages and accessories have been assembled it's time to bleed the system. Loosen bleeder plug located on the engine side of the injection pump. Operate transfer pump by hand until all air has been bled out of bleeder plug. Tighten bleeder plug.
Crack as many injector lines as you can at each cylinder and crank over engine until there is evidence of fuel at each injector. Stop cranking and tighten injector lines, start cranking engine once again and before you know it you'll have a smokin' diesel engine!

No Start Cummins Diesel Engine

2011-01-09T16:11:00.000-08:00

Cummins Diesel Engine
Here are a few tips and checks you can make when your Cummins Diesel Engine will not start. This information pertains to mechanical injection diesel engines.

Don't feel insulted with some of these checks because the simplest steps have been overlooked many times.

The rule of thumb is Check The Simple Things First!

When your Diesel engine cranks but will not start - No smoke from exhaust
Is there fuel in the supply tank? Always check the source on your diesel engine
Check electric or manual fuel shut-off.
Is the air intake or exhaust plugged?
Note: Remember, a diesel engine needs air and fuel to run
Fuel filter plugged / seperator full of water?-drain as required.
Your diesel engine injection pump not getting fuel or fuel is aerated. Check fuel flow or bleed fuel system.
Check inlet restriction to fuel transfer pump
Inspect lift pump operation. Remove outlet line and crank over engine
Worn or malfunctioning injection pump
Internal pump timing incorrect
Engine camshaft out of time

My experience with diesel engines has taught me to start from the source and work my way to the injectors.

Check the filters to see if they are still full of fuel, if not you've got a diesel engine that has run out of fuel - a no brainer. I went on a service call once and found out that the operator had filled the tank with gasoline, anything can happen!

Otherwise you have an obvious failure that you have to sink your teeth into. Replace fuel filters if the mileage or hours are excessive.

Check fuel lines from the tank to the primary filter [Fuel/Water Seperator]
Tip: I use a remote fuel container and slip the suction line before or after the primary filter. If diesel engine performance improves you know you have to start checking for faults back to the tank.

This procedure bypasses the fuel tank and lines up to that point which tells you if the problem exists in those areas i.e. restriction or split/cracked fuel line or bad pick-up tube in the tank.

Pull output line off of the lift pump on the side of the block and crank engine over and check for fuel output.

Prime fuel system with primer pump and bleed the injection pump, once primed crack injection lines at the injection pump and observe for fuel output.

In most cases you will find a problem up to this point, if not check injection pump timing or check to see if the camshaft gear is actually driving the injection pump. These failures are not common at all.

I hope these tips help you troubleshoot your Cummins Diesel Engine.