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Improved Vacuum Line Valve?

787 Views 8 Replies 6 Participants Last post by  BR
I know some truck have problems with the heat and/or A/C blowing out of the vents. Sometimes it will blow strong and other times it will cut out, only when driving and/or accelerating.

I remember someone stating there was a new, improved vacuum line valve available at the dealer that solves this problem.

Does anyone have this part number? Price?

Where is the 'defective valve located?

Is there any way to tell if I have the new valve, or basically if the heat blowing out of the vents varies on the gas pedal location, I a$$ume I still have an older vacuum line valve on my truck, right?
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Mine still does it (not as bad as before, but still bad enough) even after adding the check valve. :roll: :wall: :cuss:
That TSB only applies to 1994-1996 trucks. Are others years affect also that cover the same part and TSB?
Same thing. I did it on my '98 according to that TSB. Like I said though, it still does it with the A/C on under load. Not as bad as before, but it is still annoying.
my 98 did the same thing but now air wont come out of the vents at all. do you think that this would still fix my problem
Those little 3/16 plastic lines are very brittle and don't take much to crack and suck air. I replace plastic with rubber every chance I get.
:withstupid: had a problem with my cruise control due to the brittle plastic hardlines the factory uses.
yep, its the same check valve. but, mine still does it. i was told that a bad plenum gasket could cause it also, it makes a loss of vacuum under load or something. like said, those hard lines are junk, the ones that go to the cruise servo get cracked very easily, and the ones at the back of the motor get hot and dry and crack.
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