Let me see if I can explain this. I found yesterday that the vacuum line to what I believe is the heater is not hooked to anything. So I unplugged the vacuum feed that goes to the butterfly valve I can't remember the name) on the passenger side collector off the exhaust manifold. Here are my questions. 1. Is that going to hurt anything by not having that valve functional? Seems like the air pump has line going to this, but the air pump does not work. No belt. 2. Is the vacuum feed for that valve sufficient enough to use for the heater feed? I have not ran the truck since I did this fix to see if the heater would work a little better. thanks for the help.