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 0 3186

Articles from School Bus Mechanic

Cummins ISC Diesel Engine-Installing Complete Fuel Transfer Pump on a Thomas School Bus 2007-02-22 08:40:00 Cummins ISC Electronic Diesel Engines installed in a Thomas School Bus have a few accessibility problems.Replacing the fuel transfer pump is one component that requires some removal of surrounding parts behind the transversely mounted radiator and charge air cooler.This photo shows the transmission cooling line, power steering hose and radiator support brace removed.The fuel transfer pump is mounted at the left rear of the engine block above the starter.There are five fuel connections at the fuel transfer pump manifold and the wiring bulkhead supplying the engine ECU [electronic control unit]As noted in the previous post the pump and motor assembly cannot be inter-changed with the old housing.Here you can see the difference and why leakage is guaranteed since the new rubber formed gasket will not seal properly.This the only difference from the change-up on design, obviously an improvement from previous problems with leakage.The larger orifice on the original housing is the output side. ...

Cummins ISC Electronic Diesel Engine- cranks over but will not run. 2007-02-19 23:46:00 Cummins ISC Diesel Engines need to be analyzed using a laptop computer with Cummins Insite software.Sometimes however you can troubleshoot a no run problem the good old fashioned way by looking listening and using common sense.The fuel transfer pump mounted on the left rear of the engine is a vane type unit driven by an electric motor.The first clue was the transfer pump motor was not running at all with the ignition key on, it will charge up the system every time you hit the ignition key with a very distinctive motor noise at high rpms.So since the golden rule with electrical problems is to check the source I went to the battery and checked the multiple fuses that supply power to the engine ECU [electronic control unit]I found 3 fuses had blown indicating a possible short or high amp draw. The first thing to do was hook up a jumper wire [with an inline breaker in case there was a short]Once hooked up the fuel transfer pump started working but sounded very sickly! It was enough to l ...

Cat 3116 Diesel Engine Installation into a Thomas School Bus 2007-02-09 22:45:00 Thomas School Bus Diesel Engine Installation: This engine was rebuilt in our shop because of a wayward exhaust valve seat that didn't want to stay in one piece. So consequently everything from the head down had to be rebuilt.Step one:Tow in dead School Bus.We will utilize our shop made tow bar that has been around for a couple of decades, but still does the job.It may still make it to the "Smithsonian Institute"The Bus made it into the shop and is now waiting for some Diesel Power to give it life once again.Mounting "Allison New World" Transmission to engine flywheel housing and flexplate [much easier on the floor!]Engine and transmission are together now [the transmission is supported by the trans. jack]The entire assembly will be installed together.The bumper and frame support were removed previously which makes the installation job much easier!The complete engine and trans. assembly slid into place nicely.The engine is resting on the front and rear engine mounts. Now comes the fu ...

Thomas C2 Wiper Washer Modification - Re: washer fluid not reaching upper portion of windshield 2007-02-08 00:31:00 We found that the Thomas C2 windshields having more vertical height caused a visibility problem from poor washer fluid coverage.So we riveted an extra washer nozzle higher up on the wiper arm and used a Y connector to add the extra washer hose to the second nozzle.So far the operators have been happy with this change and it did not take a lot of parts and labor. You can also experiment with the positioning of the nozzle, on the side or the top it works both ways.Click on each photo for a larger view. ...

Mercedes MBE 900 Diesel Engine - Bleeding The Fuel System 2007-02-08 00:14:00 We experienced troubles trying to get the Mercedes MBE 900 Diesel Engine started again after it has run out of fuel.Originally we would have to pressurize the fuel tank and bleed the system at the fuel lines.Most of these engines come with a quick coupler right at the fuel filter housing. The 2005 and earlier models have to be fitted with the coupler, a kit is available from the dealer.We acquired the female quick coupler and added hose along with a stainless steel pressure tank. Note: there is a Technical Service Bulletin on the Thomas C2 School Bus models having a defective [innacurate] fuel gauge senderThe sender must be removed and tested with an ohm meter. We had some incidents on one of our C2 units running out of fuel prematurely.This tank has to be topped up with diesel and pumped continuously while a second person cranks over the engine. It works great and saves a lot of wear and tear on the starter! ...

Cummins Diesel Engine Turbo Failure 2007-02-03 13:04:00 Cummins Diesel 'C' Models come with a Holset brand Turbocharger. The operator noticed a noise coming for the engine, it was the turbocharger compressor and turbine wheels making contact with the turbo housing. When a turbocharger fails it's hard to guess how much damage has occurred and how much debris has gone through the system. In this case on one of our "C" Cummins Engines the turbo ...

Diesel Engine- Basic Principles For Beginners 2007-01-28 23:48:00 Diesel engine principles are pretty straight forward for the experienced mechanic but what about regular everyday people who have never taken the time to find out more about a diesel engine and how it works? I am going to explain in layman's terms the basic principles of a diesel engine. WHAT'S THE DIFFERENCE BETWEEN A GASOLINE ENGINE AND A DIESEL ENGINE?...a quick overview. The ...

Allison 3000 Series New World Automatic Transmission-troubleshooting a fault code 2007-01-28 21:33:00 We recently had a no shift problem on one of our 2002 Thomas HDX pusher buses. The code read on the pro-link was 45-12 which is an open circuit to the A solenoid. The A solenoid controls shifting into neutral which explains the no shift problem. Since solenoids A, D, and J feed off the same voltage source we are probably looking at a low side or ground side wiring problem. Disconnect the ...

Cat 3116 Fuel Setting 2006-11-25 22:01:00 Fuel Setting on the 3116 is checked by reading the maximum fuel rack travel. The Cat tool kit provides a long pin on a handle that inserts through the Governor link pin which has a drilled hole through the center. Then a fork shaped tool is wedged between the head and the pin to eliminate any Governor movement. The digital dial indicator arm is placed on the end of the injector rack pin on ...

High Powered School Bus Doing The 1/4 Mile! 2006-11-21 00:55:00 Check out this super modified School Bus! I would love to see what's under the hood. DON'T FORGET TO TURN UP YOUR SPEAKERS! How To Share Videos With Your Friends And Get Paid! Click Here. ...

Cat 3116 Diesel Engine-Fuel Rack Installation & Adjustment. 2006-11-11 00:40:00 Injector Synchronization This is an over view of this procedure, you definitely need the 3116 tune up kit for this and any other adjustment. The kit comes with a very detailed instruction booklet and once you have gone through a couple of settings and understand exactly what is being accomplished with each adjustment it gets easier with experience. Installing fuel Rack The fuel rack has been ... Amp

Cat 3116 Diesel Engine-Installing And Seating Injectors 2006-11-05 17:44:00 Installing and seating injectors on a CAT 3116 DIESEL ENGINE. http://schoolbusmechanic.blogspot.com/2006/05/cat-diesel-engine-model-3116.html Once the injectors are installed {REFER TO LINK ABOVE - FROM A PREVIOUS POST} they must be seated properly. Cat makes a seating tool that will do the job preventing compression from leaking past injector seats ino the fuel system. Go to this previous post ...