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Old 04-26-2013, 12:20 PM   #1
JCampbell
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What The Heck Is This? v3.0

Anyone know what this is called and what it does? It’s in the air cleaner housing and has two vacuum lines coming off the bottom. I’m sure it’s some type of emissions part, but what, exactly?

Bonus points for anyone who can tell me how to bench test, as well.
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Old 04-26-2013, 12:28 PM   #2
Turbo85GMC
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Re: What The Heck Is This? v3.0

My guess is that it's a vacuum switch, probably triggered by the intake air temp.
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Old 04-26-2013, 12:55 PM   #3
motornut
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Re: What The Heck Is This? v3.0

think its for the stove pipe
stock snorkel flap
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Old 04-26-2013, 03:11 PM   #4
beamn7
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Re: What The Heck Is This? v3.0

Its the thermal vaccum switch that opens and closes the flap in the air cleaner housing intake snout to either get hot air off the stove pipe or fresh air....
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Old 04-26-2013, 03:25 PM   #5
83GMCK2500
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Re: What The Heck Is This? v3.0

I *think* GM called it a Thermal Vacuum Switch.

EDIT: Thank you Jesse, I should've refreshed the page before replying. Walked away from PC for a while.
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Old 04-26-2013, 06:20 PM   #6
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Re: What The Heck Is This? v3.0

I don't think those actually still work on any of these trucks.
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Old 04-26-2013, 08:44 PM   #7
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Re: What The Heck Is This? v3.0

Quote:
Originally Posted by Skunksmash View Post
I don't think those actually still work on any of these trucks.
If the truck had to be etested wouldn't they have to check it?
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