Calling on all non DD people to see if they recognize this shutdown system

[zubzub]

My 6-71 has a weird shutdown air cylinder.



 I have a Shrader valve on my shut down.  It is on the air cylinder that the skinner controls.  Basically if I remove the air from it the engine shuts down.  This is something I have never really understood.  I've posted about it here with no reply so I figure it is another PO add on.  The "skinner" pressurizes the air cylinder, which seems to allow full motion of the rack when pressurized ( also and the rack has full motion when I have no air pressure), emptying the air via skinner or shrader,  "momentarily pushes the rack closed" and shuts down the engine.  This system is less than ideal as it is not very positive, sometimes I need to activate it twice for shut down.
  Anyone care to explain?

[Just Dallas]

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[Hartley]

Seems familiar to me in my scrounging junkyards a while back.

I saw something very much like that on an old stationary DD engine on a pump
system. The odd thing was that I don't remember anything but a blank cover on
what we refer to as a governor housing with a setscrew and locknut.

I think it may have been an old DD 671 or pretty close.

What you describe is a method to pull the rack closed and shutdown a fixed
speed engine( ? )...

I wonder if somewhere along the way that parts from an old stationary engine
were added to yours or maybe you have a transplant??

Sorry, The old brain just ain't up to remembering exactly about this stuff.
Been a long time ago but it was a truck and industrial salvage yard.

[fe2_o3]

Could that be used to shut down the eng. with shop air if the bus wasn't aired up?...Cable

[zubzub]

Could that be used to shut down the eng. with shop air if the bus wasn't aired up?...Cable

See this the mystery you empty the air cylinder and it shuts down, then if it doesn't quite shut down I wait a amount and do it again.

[JackConrad]

Could it be that air pressure is not released back through the air line when the engine switch is shut off because ?? and that requires releasing the pressure through the shrader valve?  Jack

[luvrbus]

That looks like a low oil shut down someone has converted over to air i saw a lot of those on 71 inline series in the marine and off road applications with 2 oil lines 1 line where the valve is on yours ,do you have a photo of the governor  


good luck

[johns4104s]

To help you with the skinner valve problems connect up a two manual valves in the system. This will allow you when the skinner valve acts up to release the air from the rack and start the engine.

John

[zubzub]

To help you with the skinner valve problems connect up a two manual valves in the system. This will allow you when the skinner valve acts up to release the air from the rack and start the engine.

John

Actually that is the cool thing about this set up, air cannot hold the rack closed for more than a moment, and even if it did the Shrader could relieve it.

[gus]

Zub,

That valve does not look like on my 4104 w/671 which I think is original. I'll make a photo of it and send to your email address if you like. I tried to post one here but it is too large, only 128kb allowed here.

As I've said before, it is supposed to use air pressure to shut down. Mine will continue running with no air pressure even with the switches off.

[Just Dallas]

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