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Old 07-17-2016, 12:56 AM   #1
NorCalK5
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Front differential vacuum tube

Where does the front differential vacuum tube lead to and attach to?

Mine just ends near the engine into mid air. That can not be good.

Please help....Thanks!

1972 Blazer
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Old 07-17-2016, 01:30 AM   #2
truckster
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Re: Front differential vacuum tube

It's a vent tube, not a vacuum. It just provides atmospheric vent so pressure doesn't build up and cause a leak.
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Old 07-17-2016, 05:29 AM   #3
Bigdav160
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Re: Front differential vacuum tube

Install a vent cap on the hose end. The hose should be clamped to top of the frame
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Old 07-17-2016, 03:27 PM   #4
tjsblazer
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Re: Front differential vacuum tube

Rh frame rail where the upward bend is in the upper surface.
I think may be shared with same hole as battery cable from above?
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Old 07-18-2016, 09:09 PM   #5
robs71k5
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Re: Front differential vacuum tube

Anyone know where to buy the vent cap ?
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Old 07-18-2016, 09:32 PM   #6
bluek5
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Re: Front differential vacuum tube

Quote:
Originally Posted by robs71k5 View Post
Anyone know where to buy the vent cap ?
Not sure if the vent line is 5/16" or 3/8". Here is a 3/8" from Inline tube.
http://www.ebay.com/itm/1964-81-GM-a...dW5ERc&vxp=mtr
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Last edited by bluek5; 07-18-2016 at 09:35 PM. Reason: Picture
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Old 07-18-2016, 10:25 PM   #7
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Re: Front differential vacuum tube

The donor 2003 4X4 GMC Sierra I got my engine from used the same vent plugs, so you can grab one from the wreckers.
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Old 07-21-2016, 12:17 AM   #8
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Re: Front differential vacuum tube

Mine were 5/16. I bought some dorman part that look identical. I'd imagine that you could get them at any jobber supply place like Napa, etc.
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Old 07-22-2016, 12:04 AM   #9
DeadheadNM
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Re: Front differential vacuum tube

These are still available through GM also...
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