Hey-I’ve got a vacuum leak on the purple vacuum hose which connects from the HVAC mode selector to the actuator under the dash. Where is the location of the Hvac actuator that connects to the purple hose. The problem is airflow goes to the default upon acceleration floor/defrost. Upon crimping the purple vacuum hose the leak stops, but I have now lost the bi level ac function the hvac mode selector. Any ideas on how to fix this cream puff of 71,000 miles-no rust.

Thx so much, and happy Father’s Day to the dads out there.

 

Do you know where the leak is? I would just cut the hose at the leak and then crimp a splicing nipple in.

If you sign up on AutoZone.com, they have repair guides and may have the diagrams for the vaccuum lines. (I'm not sure - they are definitely in GM's factory service manuals.)

 

I believe the actuator has failed because the air conditioning bi level setting comes out by the feet and not at the vents. I crimped the purple hose temporarily so that it stopped the vacuum leak completely. I’ll check out the autozone stuff-it appears the actuator may be buried in the dash somewhere unrepairable by the diy’er.



QUOTE=wssix99;20261122]Do you know where the leak is? I would just cut the hose at the leak and then crimp a splicing nipple in.

If you sign up on AutoZone.com, they have repair guides and may have the diagrams for the vaccuum lines. (I'm not sure - they are definitely in GM's factory service manuals.)[/QUOTE]

 

Behind the dash is a system of ducts, which takes up most of the real estate inside the dash. The actuators are in these ducts. You should be able to get to them by taking off various parts of the dash trim: (This is a 2nd gen car, but the idea is the same.)




Here's a diagram of the hose routing for the 3rd gen. (The duct diagram is an abstract one and not a technical representation.) The 4th gen car should also be similar:




No matter what you do, having a Mighty Vac really helps diagnose these things: (You can unplug the hoses at the control panel and apply vaccuum to them and manually control the actuators to isolate/control leaks.)