Monday, October 8, 2012

Run Away Detroit Diesel 6-71

It really wasn't a runaway.  I just could not turn the engine off.

I have recently acquired a 1960 GMC bus.  It is a model 4104.  The engine is a Detroit Diesel 6-71.  This is a two stroke diesel.  Before I got this bus I basically knew nothing about diesel engines.  Didn't even really know that they came in a two stroke version.  So I joined a BBS and read up on what I have.  I got a maintenance manual, a parts manual and a operations guide.

The first time I moved the bus I had a guy who was a diesel mechanic come over and help me start it and we went over some of the systems.  Then I drove it about 5 miles and parked it in a warehouse.  Now I want to move it outside.  I started the bus up and the air system would not work.  This bus has air brakes and other systems that require air pressure to run.  After a few minutes of running I decided to shut the engine down  and hunt for the  problem.  The only problem was the off switch did not work.  I switched it off and it kept running.  I had read somewhere about an emergency shut off switch and there was this switch that said as much underneath it.  So I went to the manual and read about it and after confirming that this was in fact that switch, I flipped it.  Still the engine kept running.   So now I  am beginning to worry.  I went back to the manual and read about how to manually flip of a lever that cut off the air flow to the engine.  Sounds reasonable.  So I go look for something that looks like what is shown in the manual and can't find it anywhere.

Finally, I swallowed my pride and call an old neighbor of mine that used to work on diesels and ask him what to do.  I must admit that I did feel kind of stupid when he said to cover the air intake with a board and that will shut off the engine.  I should have thought of that.

So now I am going to do a complete inventory of what the  parts are in the engine compartment.  I have checked with the photos in the manual and they are so bad that I can not tell what the various parts are anyway.   Maybe I should publish a better manual?