Questions and Answers
Cutlass Vent Problem
Q.1996 Olds Cutlass Supreme L, 3100 V-6, 2 door, 96,000 miles. When I accelerate, the A/C vent control door (diverts air to dash or floor) changes from dash to floor. After the engine levels off, it changes to blowing through the dash again. The blower is working fine and Max A/C is fine. I'm sure it's a vacuums leak, but I can't find it.
A. I had one of these that the vacuum storage tank had been collapsed from vacuum being pulled on it constantly. A real helpful tool would be a hand held vacuum pump. This tank should be under the hood. Trace all your vacuum lines by hand. One may just fall apart in your hand. If not, you can put the pump on and see if it holds a vacuum. There is one line off the engine that goes to the HVAC & cruise. Also there may be a vacuum check valve that is a tee. This is where the two circuits split to their own lines. They can leak as well.
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