2006, 5.4- No vacuum to brake booster after backfire
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?