School Bus Mechanic Videos, pictures on repairs and maintenance on Diesel Engines and School Bus components and systems. Lots of "How To" repair information from a Certified Commercial Transport Mechanic. Comments and Questions Welcome! Statistics Unique Visitors: Total Unique Visitors: Outgoing: Total Outgoing: 0 0 10 3196

Articles from School Bus Mechanic

Cat 3116 Engine Synchronization Video Tutorial 2007-11-18 16:21:00 Cat 3116 Diesel Engine Setting Synchronization is a multi-step operation and requires the Cat Tune up Kit. Some standard hand tools will work but most of the setting tools are specially designed for this purpose. NOTE: Remove fuel solenoid before starting synchronization, this allows free rack movement.Below is Step One:Calibrating #1 InjectorStep Two:Setting Up For Injector SynchronizationStep Three:How To Adjust Injector SynchronizationThis is the hardest step to get around {especially for the first time} but comes much easier with repetition. The Cat 3116 Diesel Engine is a fussy engine to tune up but it pays you back with great performance. ...

Used School Bus For Sale Review 2007-11-11 10:21:00 Used School Bus For Sale-1993 Bluebird Pusher Looking for a used school bus for sale can be a lot of work and when searching all over the country for a deal there's some reluctance in most people when they can't touch what there thinking of buying and not knowing the seller's credibility.I've been using Ebay for years and it's the top "brand name" for buying and selling on the Internet. Sellers and buyers are held accountable with a feedback score from previous transactions that everyone can view, when you click on a product all the seller's history is located at the top right hand corner. Ebay auctions usually run for 10 days at a time and you are notified by email if you've won the auction item or the it's come to an end.So I'm going to write random reviews on a used school bus for sale on Ebay that I think meets all the requirements for price and condition.Below I will make comments on the vehicle description [italicized with the * sign] to let you know what my opinions are ...

Internatonal School Bus DT 466E Cam Sensor Replacement 2007-11-10 00:30:00 Today we're working on a Thomas/ International School Bus that requires a Cam Sensor. It's located in the front of the engine in the gear cover and reads engine rotation sending a signal to the Engine Electronic Control Unit. The Engine will not run with a failed cam sensor and the Pro-link diagnostic tool will verify the sensor failure.The depth is checked with a dial indicator that has been calibrated according to the new sensor part number. Shims may be removed or added to get the proper clearance which is between .025 and .030 of an inch. The belt has to be removed and the engine rotated twice to check the runout and get an accurate reading.Here's a look at the calibrating kit that must be used to read the depth of the bore where the sensor is mounted. There can't be any interference fit, this will damage the sensor. The new sensor is seen here on the left while the rest of the calibration tools are nestled in the carrying case.That's all there is to it when changing the cam ...

What Year Was The First School Bus Manufactured? 2007-11-08 00:50:00 What year was the first School Bus manufactured? School Bus History: Wayne Works, predecessor of Wayne Corporation was founded in the U.S.A in 1837.By 1886, and possibly earlier, it is known that the company was making horse-drawn school carriages which many people referred to as "school hacks," "school cars," "school trucks," or "kid hacks."("hack" was a term for certain types of horse-drawn carriages.) In this era, in rural areas, it was very common to use farm wagons to transport children to schools throughout North America where sleds were adapted for heavy winters in northern climates.In those days, most elementary children in rural areas attended one-room schools. A typical kid hack would serve all the farms in the area of the school, and usually transport under 20 children.The horse-drawn kid hack is considered to be the precursor to the modern yellow school bus.In 1914 early designs of "kid hacks" were attached to early motor vehicles by the Wayne Works in Richmond, Indiana. As ...

Thomas Bus Heater Blower Motor Replacement 2007-10-27 09:13:00 There are 4 Front heater blower motors on the Thomas School Bus Saf-T-Liner Model. With Winter on it's way this is an important maintenance area, defrosting of the windshield has to be accomplished quickly.The heater blower motors also serve as defrost motors with a quick change up on the controls. Each motor has 4 wires for high/low speed and 2 grounds.The direction can be reversed using the ground wires. One is grounded directly while the other is connected internally back to the motor, reversing these 2 will change direction.This Thomas Pusher Bus is a 1992 model, removing the middle and left side panels will allow access to all 4 heater blower motors.The tandem motor in the middle looks after main defrost and heat while each motor on the ends provide floor heat to the driver and defrost/heat to both ends of the cab.The main failures on these motors are dry bushings causing noise and seizure and blower cage noise. ...

Allison Automatic Transmission Wiring & Troubleshooting 2007-10-14 21:55:00 The Allison Transmission Control Unit on the 1999 Saf-T-Liner is located under the floor directly below the driver. There are 3 plug-ins which is an easy way to tell this is a W-TEC 3 system [World Transmission Electronic Unit 3rd generation]. The Transmission vehicle speed signal enters here and exits at two different plugs, one for the speedometer and the other to the Cummins ISC ECU. We will trace the exiting wire from the ECU that provides our Vehicle Speed Signal since that is the code and the speedometer is operating normally. Since we have speedo operation that gives us an obvious clue that the incoming signal to the Trans ECU is OK.[resistance should be checked regardless]The wire we want to trace goes from the Trans ECU to the VIM [Vehicle Interface Module]Removing the dash back cover makes this check MUCH easier. Remove the cover from the VIM The VIM is an interface between the Trans ECU and the chasis wiring. Various operations are accomplished through this module like the ... Amp

Allison Automatic Transmission Troubleshooting and Repair 2007-10-11 00:36:00 I'm working on an Allison MD 3000 Automatic Transmission with a wiring problem. The trouble started with a fault code on the engine side of a 1999 Thomas Saf-T-Liner equipped with a Cummins ISC Electronic Diesel Engine.[Click Pic To Enlarge]The Cummins fault code was "241" meaning a loss of the Vehicle Speed signal to the Engine ECU, the amber warning light flashes on the dash alerting the driver. Without a vehicle speed signal the engine ECU [electronic control unit] does not know if the bus is moving or stationary so the exhaust brake and high idle will not work. There was also a drivability problem with loss of power which was related, since the fuel system also needs to know how fast the bus is travelling to regulate fuel pressure.Normally the bus has to be moving over 5 mph and running over 1000 rpm for the exhaust brake to work and has to be parked for the high idle to come on. Since the output speed signal is supplied from the transmission output speed sensor we have to start ...

Testing A Starter Solenoid 2007-10-04 08:38:00 Check out this excellent video on Electromagnetism. This is the principle that solenoids and relays use to provide the most efficient electrical circuits. It's over 10 minutes long so grab your favorite beverage and have a look.The principles here will give you a much better idea how components work like a starter solenoid. Following this video is my own on bench testing a starter solenoid which connects the Battery to the starter motor and engages the starter drive with the engine flywheel.Below is a demonstration on bench testing a starter by simply connecting battery supply to the solenoid positive terminal and the ground terminal at the starter motor.The switch terminal which is marked "S" is the signal from the ignition switch that energizes the coil in the solenoid and turns it into an electromagnet forcing the contact plate to connect the main battery power to the motor. Here is an older post on the disassembly & repair of a Delco 37 MT Starter ...

Basic Electricity How It Works 2007-09-28 15:03:00 Basic Electricity applies to any type of machinery running on a 12 Volt Direct Current system. Once you see how it works it's much easier to understand, instead of making it complicated I will explain the basics in layman's terms. This is the chasis electrical panel on a 1995 Thomas Saf-T-Liner[pusher]. note: Click on the Photos to Enlarge It looks a lot more complicated than it really is. Any 12 Volt electrical system has a source of power from the batteries, in this case we run on 3 top post 900 CCA [cold cranking amp rated] batteries.That's a lot of juice available to supply voltage to the body and chasis circuits, but there are environmental and mechanical factors that will cause a severe voltage drop if not detected.Voltage is like a river, the heavier the flow the stronger the current. If there's a dam down river this will cause resistance and restrict the flow. If the source [the river] is cut off so is the flow.Any resistance between the battery and the load will cause a vo ...

Spring Brakes and What You Should Know! 2007-09-27 16:31:00 Here's a great explanation on the Spring Brake that holds all that truck and Bus tonnage from rolling away. When doing a pre-trip the springs must on and to test them for holding power you give the throttle [engine running in gear] a quick hit with your foot. Don't put your pedal to the metal 'cause nothing is going to hold back that kind of torque!The safety factor is much higher with spring brakes because the highly commpressed spring is now factory clamped so it's left alone and no one can get injured.[years ago they were serviceable and there were fatalities]Check out this pdf below: Thanks to Mac over at http://skoolie.netSpring Brakes PDF InstructionsHere's a previous post I made about Spring Brake assembly replacement:How To Replace A Spring Brake Assembly ...

Testing Automotive & Heavy Duty Batteries 2007-09-27 01:12:00 Here's a great video on testing a battery using the proper battery tester . There are many different battery testing models and they all work, all you want to accomplish is to put a load on the battery and read the voltage level. You need to know the CCA [cold cranking amp] rating labeled on top of the battery, then draw 50% of that off the battery with your tester for 10 - 15 seconds [the tester has a carbon pile that absorbs the heat from the heavy draw].A general rule of thumb I use is a battery voltage drop of no less than 9.6 Volts after a 10 second load of 50% of the Cold Cranking Amp Rating. One important factor is the battery must be fully charged before testing, preferably around 12.6 Volts.A battery tester is affordable but if you don't own one & you're not sure of the condition of your battery then a quick load test at a repair shop is worth it. A reputable shop won't charge you for the test if you buy a battery from them [since the test only takes less than a minute ... Amp

Diesel School Bus in UK Running on Rape Seed Oil 2007-09-22 19:02:00 Here's an interesting video about a company called Regenatec that have developed a bio-fuel from rape seed oil. This is very impressive since it reduces emissions by 80% ...

Bus & Truck Air Brakes System-Bendix AD-9 Air Dryer 2007-09-22 14:33:00 The Bendix AD-9 air dryer is easily serviced by disassembling it from the frame and removing the bottom cover bolts. The unloader located on the bottom housing can be removed and a kit installed. The kit comes with new o-rings, spring, valve and seat. The main filter which is filled with dessicant absorbs the oil and moisture that accumulates in the air brake system.Since the air compressor creates heat this causes moisture to build up, so this is why air brake systems have an air governor that unloads the compressor at 120 p.s.i. and signals the dryer to dump the build-up of water & oil in the bottom housing to atmosphere. That's the quick air release you hear when building up the air system, the air guage should be reading a minimum of 120 p.s.i. The dessicant filter has a threaded stud attached so it can be easily removed during a service. The Bendix AD-9 is a very reliable component and is usually trouble free but if you notice a lot of oil coming from the bottom housing exhau ... Amp

A Sexy Woman Standing By A School Bus! 2007-09-21 20:09:00 Being surprised by a beautiful woman at work has it's advantages after looking at grease and dirt and oil etc. there's nothing better than rolling out from underneath a School Bus and seeing a nice looking woman in front of you!Well this woman happens to be my wife who doesn't mind walking through a greasy repair shop to see her husband.The bus she's standing beside is a 2006 Thomas C2 that I had a few problems with [even though it's fairly new minor problems do occur]. I will go through them on my next post,it's an air system problem that you don't want to miss, so please check back. ...

Found a Used School Bus For Sale? What You Should Know... 2007-09-16 12:01:00 There are thousands of Used School Buses For Sale but you still need to use your due diligence when checking it out.A visual checkover is the first thing to do when looking the bus over but internal information can help you make a more confident decision. Looking at the past life of a School Bus will tell you the whole story and most of them will have a thorough record starting from the first day it turned a wheel.What's the mileage? 2-300,000 KM is an average [We've had buses run over 400,000 km but that isn't a huge factor depending on the running gear and PM program.]Was it on a Preventitive Maintenance Program from new?Who owned it previously? A Private or Government facility? [Government preferred]Is there a log book or maintenance records? [Any signs of a lemon?]Is it Gas or Diesel? [Depending on the size of bus Choose Diesel]Make and model? [I would choose a THOMAS over anything else]Engine make and model? [Cummins C & Intn'l DT 466 very reliable!] Gas engines are usuall ...