I started my 2006 F150 yesterday and it backfired. Its only got 35000 miles on it and is rarely driven. After starting it again I put it in gear and got a big surprise when the brakes didn't work!
I got it home and pulled the vacuum line off the vacuum booster and there is no vacuum. Listening I don't hear any signs of vacuum leaks, the hoses all appear good with no weathering, splits or cracks and the engine runs just fine?

Is there a check valve or something else that could be plugged or jammed from the backfire?

 

Pull the line completely off and check for a blockage. While its off check at the port itself for vac. Something (crude) probably came loose and is blocking the line or vac port. Might want to explore why you had a backfire in the first place.

 

Been doing some research and found Ford did a recall on the 05-06 F-150s with the 3 valve 5.4 for this very reason. Now all I have to do is get it into a dealer for replacement.

 

You should have received a letter from Ford about this recall. I am not the original owner of my F150 and I did over a year ago I believe. The Dealership had my truck for most of the day.

 

Took it in Saturday and 3.5 hours later I had it back.
While I was there I asked about the spark plug fiasco and was told it would be $272 to replace them plus an additional hours labor for each one that broke. Ford really screwed up on this one and I am very disappointed thye are not standing behind it. This is my fifth Ford pickup and have had 3 new Ford cars for the wife and thats how they treat their loyal customers?