Well when I put my lift on, I accidentally broke the lines going down to axle. The cad vacuum lines that is. Well to make a long story short, you cant just buy the flex part of the lines going down to front axle, you have to buy everything back to the t-case. So the mechanic at the local dealership told me to just get some regular vacuum tubing and make my own, thats what he does, plus I could make it any length I wanted given the lift. So I make my own and all is good. Then I'm going down the road and now the heater keeps defaulting to defrost off and on. WHen I'm riding down the road and it defaults to the defrost, if I let my foot up off the gas it will come back to where its supposed to be. This means I have a vacuum leak somewhere. I checked my homade lines and they are all good, I'm thinking its a just a coincidence that it happened at the same time. Anyways, been over the complete truck and cant find anything off or missing. Has anybody had this vacuum leak trouble before? Is there somewhere on these trucks that the lines like to come off or crack?