I've done a few searches on this, and found some good info, but I need a little more specific help. One day I moved one of the controls and it started hissing and never stopped. I tried to pull the controls out a little to see if I can spot where the leak is but it only came out a little, and I didn't want to pull hard and break something. So my questions are:
1. Can I pull this thing out from the front of the dash, or do I need to get behind it somehow to disconnect stuff?

2. Is there some parts that can be replaced back there, or do I need to replace the whole control unit? (if so where is the best place to get one)

3. Am I way off with this conslusion that it is this control?

Oh and the truck is a 91 s-10 4x4 with the 4.3L engine

Thanks in advance

 

Much of the HVAC system is vacuum controlled. Sounds like one of your vacuum lines finally gave up and broke. You will have to remove the HVAC control head (the whole assembly) and determine which hose is the culprit.

 

For me to get at the vacuum lines, can I remove the control head just be taking out the two screws and pulling it out, or do I need to take more of the dash apart?

 

I just tried removing the controls again, and it seems like the cable on the left side that is connected to the temp control is keeping me from pulling the whole control out, how do I disconnect this cable?

 

I've had to take my AC control off a few times for different things. The temp. control cable on mine is held in by a little red piece of plastic with a peg that falls into a slot on the AC controls. You have to depress that little slot it falls into and then you should be able to pull the cable free. Carefull not to break it, as the plastic on there is getting a bit old now.