trouble shooting emergency shut down soliniod

[johnjem]

hey guys just cking all my nice buttons on my dash <started up the beast.and tested out some toggles just in case i did try the emergency shut down toggle <good to make sure it does work> and nothing
cked for power to switch and after switch going to the engine <good> i even have power to the stud on the rear of the air shut down soliniod  but it does not move,with engine not running i set the cam off and moved plunger up and down moves ok! reset the cam on the plunger<retryed and nothing ,i restarted bus and hit the emergency toggle again and nothing still have power on the rear stud and no power when the toggle is off<!so what do u think?

[DrivingMissLazy]

Make sure you have air pressure built up before you try the emergency shutdown, otherwise it will not work.
Richard

hey guys just cking all my nice buttons on my dash <started up the beast.and tested out some toggles just in case i did try the emergency shut down toggle <good to make sure it does work> and nothing
cked for power to switch and after switch going to the engine <good> i even have power to the stud on the rear of the air shut down soliniod  but it does not move,with engine not running i set the cam off and moved plunger up and down moves ok! reset the cam on the plunger<retryed and nothing ,i restarted bus and hit the emergency toggle again and nothing still have power on the rear stud and no power when the toggle is off<!so what do u think?

[FloridaCliff]

Richard,

Good Call!

As Yogi Bear was known to say " Hey Boo Boo, I am smarter than your average Bear"

Cliff

[DrivingMissLazy]

Cliff, maybe I should have added "don't ask me how I know this" LOL
Richard

Richard,

Good Call!

As Yogi Bear was known to say " Hey Boo Boo, I am smarter than your average Bear"

Cliff

[FloridaCliff]

Richard,

Fair enough!

Don't ask me how I knew either...LOL...

Cliff

[Stan]

There seems to be confusion on two different items. As far as I know, the emergency shut down on a DD two stroke is an over center flapper in the blower intake. When power is applied to the solenoid, it pulls the pin releasing the cam on the end of the flapper shaft, which falls over of its own weight.

If there is power on the solenoid and a good ground between the solenoid and the blower intake pipe it should work or else the coil is open. My first check would be to connect a ground wire from the solenoid frame to a known good battery ground. If it still won't pull the pin, you need a new solenoid.

[johnjem]

thanks stan  yes it is a electric soliniod that closes the flapper and shuts air off in the blower, i will try to ground out soleniod!
there is no air on this soliniod

[johnjem]

nope also on a 8v71 i still have the normal air shut off soliniod but a emergency soilniod

[gus]

Stan has it right, the emergency shutoff is electro/mechanical, it has nothing to do with the air pressure system. The elect solenoid releases the spring loaded flapper cam which closes off the air to the engine. PLEASE do not use this switch with the engine running except in an actual emergency. Always check it with the engine off.

Normally the Engine Run switch must be on for the emerg switch to work.

If you have power at all those places you posted you have essentially narrowed it down to the electric solenoid, as Stan said.

[FloridaCliff]

Darn,

John put emergency shut down two places and I still thought "Shut Down"   

Well, Gus is right, that Stan is Right.

Richard and Cliff are mistaken, and "the wheels on the bus go round and round".  LOL   

Cliff

[DrivingMissLazy]

You are correct Cliff, I was mistaken. Gus and Star are correct.

The way he wrote it initially I thought he was talking about the air operated solenoid on later engines. I have actually used the flapper emergency shutoff on my first bus, a 4104 with 6-71. I really thought that went away with the 4104. This is why it is so nice to have so many people participating on the board and calmly discussing things.
Richard

Darn,

John put emergency shut down two places and I still thought "Shut Down"   

Well, Gus is right, that Stan is Right.

Richard and Cliff are mistaken, and "the wheels on the bus go round and round".  LOL   

Cliff

[johnjem]

my bad u guys i sorry i confused u all i did say ( air ) shut down sorry guyS i was chewing gum at that time lol    i will ck on a new electro valve

[Stan]

johnjem: Your terminology was correct but the order of the words caused the confusion. "Air shut down solenoid" compared to "solenoid that shuts off the air". Normal shutdown is a solenoid air valve (air solenoid?) that shuts off the fuel.

BTW: Did you check the solenoid coil with an ohmeter?

[johnjem]

No just with a test light, very bright< 

[TomC]

Unless the engine in your bus has not been rebuilt in the last ten years, you most likely have the updated or turbo seals on the blower.  I'm always hearing about not trying the emergency blower air flap because of possibly pulling the seals out-but have never heard of anyone in real life having this happen.  Anyone out there have it actually pull the seals out of the blower?
Sometimes the cam maybe a bit rough or sticky.  While I wouldn't suggest oil, just run your fingers over it to make sure it is smooth.  Once running a truck with a 6-71, I hit a bump going around a corner and it knocked the kill closed.  Needless to say, I know they work.  Good Luck, TomC