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Transfer case vacuum switch change

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Old 09-27-2012, 02:35 AM
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Default Transfer case vacuum switch change

I need to change my transfer case vacuum switch and need to know if it can be very messy or can be done by placing few rags under the truck. Will oil come out of the transfer case when I remove the switch? And how much oil will I lose?
Any tips on how to change it are welcome
 
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Old 09-27-2012, 09:33 AM
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You shouldnt lose any oil. Sneak in there with a 1 inch wrench and uncrew it (i may be wrong about the size). It shoulnt be in there too tight. make sure not to mix up vacuum lines.
 
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Old 09-27-2012, 10:29 AM
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Originally Posted by AndrewO1991
It shoulnt be in there too tight. make sure not to mix up vacuum lines.
Thanks for the reply Andrew!
What do you mean with "it shouldn't be in there too tight?
As for the vacuum lines, I know that one is the vacuum from the engine, the 2nd goes to the actuator under the battery, but it's the 3rd that I have a problem with! I know that it combines with another line from the transfer case and goes up to the engine bay with a small filter on its tip. Right? Well mine has like only 3 inches on the switch without a combiner or anything, and I don't have a 3rd line for it. Now I can easily run a 3rd line from it to the engine bay, but I can't find where's the plug on the transfer case where it should combine with! Should I just run a line from the 3rd plug on the switch to the engine bay with a small filter? Will I have water get into my transfer case if I don't find that plug on it to close it or combine it with the switch? And I find it strange that the 3rd line's tip in the engine bay should be left open with a filter! (Unless I'm wrong)
 

Last edited by 89 Blazer Lebanon; 09-27-2012 at 10:43 AM.
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Old 09-27-2012, 02:57 PM
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that line is a vent to atmosphere to release the actuator.
 
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Old 09-27-2012, 03:05 PM
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If any oil comes out then you have bigger problems. The switch is on top and can be a pita to get to.


My vent runs up and is zip tied to the trans dipstick. If im in water deep enough to get in it i'm more worried about the water getting sucked into the engine.
 
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Old 09-27-2012, 05:28 PM
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Originally Posted by cannon
that line is a vent to atmosphere to release the actuator.
Thanks for the great info! But what about the combiner and that line from the transfer case? It's the transfer case that I'm worried about!
 
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Old 09-27-2012, 05:41 PM
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Originally Posted by neo71665
If any oil comes out then you have bigger problems. The switch is on top and can be a pita to get to.


My vent runs up and is zip tied to the trans dipstick. If im in water deep enough to get in it i'm more worried about the water getting sucked into the engine.
If oil comes out when I remove the switch what would that signal?
If all is right, why would you have water sucked to the engine? That would mean that you have vacuum leak!
 
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Old 09-28-2012, 12:24 AM
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The 3rd line is a vent, it vents vaccum from the actuator system and is a vent for the transfer case. That is why it has 2 lines into one. One on the switch and one on the transfer case vent tube. Typically leads somewhere in the engine bay high up.
 
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Old 09-28-2012, 04:37 AM
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Originally Posted by AndrewO1991
The 3rd line is a vent, it vents vaccum from the actuator system and is a vent for the transfer case. That is why it has 2 lines into one. One on the switch and one on the transfer case vent tube. Typically leads somewhere in the engine bay high up.
I can't find the plug where the transfer case vent is! Is it somewhere on top of the transfer case that I can't see? Do you have any photos or schematics of where the vent line connects on the transfer case?
Thanks again Andrew!
 
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Old 09-28-2012, 12:48 PM
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If oil comes out (it will be tranmission fluid btw) its a sign the seal on the trans is out and its dumping its fluid in the t-case over filling it.





that should explain it
 
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