OK looks like I'm late to this game. Glad you got it sorted out. I had the same thing happen but my problem was that the rubber cap I had put on that inlet rotted and fell off. I replaced it but 6 months later it was cracked too. I ended up getting some vinyl caps and have not had any trouble since. I zip tie it on there too.
Dan

 

^^^

+1 on the vinyl caps.

The rubber ones just don't last.

 

Where did you pick those vinyl caps from? I just purchased another set of those chinese crumbling rubber ones that last about a year.

 

I think I brought mine home from work. They come on the small tubes they package end mills in. I think someone else said they got some at NAPA. I would try any of the auto parts stores.
Dan

 

yeah thats exactly what i did! you can get them at Autozone, Advanced Auto, Pepboys, etc. pretty much any auto parts store under the vacuum line section

 

Got mine at AutoZone.