1986 Bronco Vaccuum Line 4x4 Shifter -- Question

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Smafugula

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1986 Bronco 5.0l 302 EFI w/ man. trans and auto locking 4x4 hubs

Was farting around tonight looking at all the new leaks popping up from bringing this neglected 86 Bronco back to life and saw a vacuum line loose under the truck, near where the 4x4 shifter goes. Do yall know what that vacuum lines for? It is broken and I'll have to figure out how to replace it since it goes all the way up into the truck, guess take the boot off from in the cab? It seemed like it didn't want to come out freely. Anyways any insight is appreciated.
 

Tiha

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Someone else will have to chime in here, but I cannot think of any vacuum lines on a man trans or transfercase. Maybe it is a vent hose?
Or could it be an emissions line running to the rear tank for vapor recovery?
 
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Smafugula

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Someone else will have to chime in here, but I cannot think of any vacuum lines on a man trans or transfercase. Maybe it is a vent hose?
Or could it be an emissions line running to the rear tank for vapor recovery?
I’ve done some web searching. I think it is a vent hose. Not sure what it is for but it definitely goes up into the cab where 4x4 shifter **** is. Truck does have auto locking hubs
 

miesk5

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Yo Smafugula,
86 Bronco Emission Vacuum has a hose to HVAC System
download.jpg
download (1).jpg

For posterity:
The C6 has a vacuum line.
Pull the vacuum line off the modulator If fluid comes out of the vacuum line your modulator is no good.
Check vacuum line to modulator from engine intake manifold source.
 
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Smafugula

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Yo Smafugula,
86 Bronco Emission Vacuum has a hose to HVAC System
View attachment 28970
View attachment 28971

For posterity:
The C6 has a vacuum line.
Pull the vacuum line off the modulator If fluid comes out of the vacuum line your modulator is no good.
Check vacuum line to modulator from engine intake manifold source.
This is by the 4x4 shifter lever in the cab. The hose is under the truck leading to the transfer case from the 4wd shifter in the cab. Don’t think that would have something to do with HVAC? I can post a pic
 

miesk5

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Yo,
Pinch the hose to see if it stops HVAC VACUUM doors from operating. Not Much or No Heat in an 86; "...You should also check the blend door to see if it's switching to hot. If you pull the glove box out, you can see the cable going to it on top of the ductwork as you move the slide. If it has NO resistance or if it binds, then the door might have broken away from its film hinge..."

Or as Tia advised.


NP208 Transfer Case doesn't need a vacuum source.20211121_121612.jpgTransfer Cases.jpgScreenshot_20211121-110441_Chrome.jpg
 

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