Vacume Leak Under Dash

[Charles Young]

My 86 T has what sounds lie a vac leak under the dash. It will start/stop depending on AC control settings. Starting or stopping the "leak" sound does not noticeably affect the way the engine runs/sounds. I would appreciate any info or experiances you guys may have had with this type issue.... where to start?
Thanks!!

 

[87geeinn]

It could be one of the many hoses going to the climate control unit but hard to tell until you start disassembling things.

 

[Nick Micale]

A common problem with the AC control unit is the rotating vacuum switch comes apart.

Pull the control head from the dash and see if this plastic part has separated?

 

[Charles Young]

Thank you I'll do that!


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[terry richards]

Apply 8 to 10 lbs of air to h vac supply line on firewall,go under dash and listen and feel for air leak

 

[Charles Young]

A common problem with the AC control unit is the rotating vacuum switch comes apart.

Pull the control head from the dash and see if this plastic part has separated?

Ok finally getting back to this. How do you pull the control head?

 

[psycho6cyl]

Take radio bezel off remove radio and unplug everything then remove ac controls

 

[psycho6cyl]

Like nick says sometimes it's that rotating plastic piece. Mine looked like it was a loose hose and even stopped when i put my finger near hoses but it was actually plastic piecd

 

[Charles Young]

Thank you!!


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[Charles Young]

A common problem with the AC control unit is the rotating vacuum switch comes apart.

Pull the control head from the dash and see if this plastic part has separated?

Hey Nick - I think you nailed it! The leak increases/decreases as you press on that switch. Now what? Can you just replace the switch? Any vendors have it?
Thanks!!

 

[Charles Young]

Never mind, found they have them on line at least at Gbody.

 

[Charles Young]

Is the vac switch still available from GM by chance? Other vendors?


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[Charles Young]

Found a spare vac switch but it appears to leak too. Here's the dumb question... How important is it to get this fixed or can it wait " til I get to it"?


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[Charles Young]

Both vac switches in the AC unit were leaking. Got the bigger one at NAPA but had to get a little creative "repairing" the smaller 2 port one. Thanks for the help guys!!!


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