The other day I noticed that my drivers side hub was clicking. I looked and saw that the dial was not all the way to the auto position. I tried to turn it by hand but couldn't. I grabbed a channel lock and turned it to the auto position. But in doing so I noticed that I could see the o-ring around the **** had ripped and a small piece was sticking out. I knew it would probably have a problem as I was leaving on a 5 Day hunting trip soon. I got a set of mile marker hubs from amazon in 2 days and installed them. I totally forgot about plugging off the vacuum lines. Is it necessary to plug off the lines? I don't know if I'll have time to work on it before leaving on the hunting trip.
Thanks

 

If you have vacuum leaking your HVAC controls will only vent out the defrosters. Vac leaks are not ever a good thing.

 

Ok. I was thinking that the hubs worked off a vacuum pump and not from engine vacuum. I don't think it's a continues vacuum. so maybe it wont throw a CEL. Thanks for the replies.

 

Just shove a screw with a little RTV or something in the end of the vacuum lines.