06 lariat , When I fully depress brake pedal at a stop it will go almost to the floor and I hear a strange type of creaking sound coming from under the hood. If I shut the eng. off the brake pedal is rock solid and stays up like it should. Has anyone else experienced this?

 

I haven't experienced that, but it sounds like a power brake booster vacuum leak. Could be the vacuum line. Ford had a recall on 06's for this. I took my 06 in and they inpected and installed a new vacuum hose.

 

Don't know if it applies here, but that can indicate time to replace the pads.



John

 

Could also be an adjustment problem. I know dics aren't adjustable, but if one caliper isn't fully engaging that would make a pedal mushy. If the emergengy brakes aren't fully released could also effect brake pedal. Air in the lines could also cause this. Best advice is to follow the diagnostic procedures spelled out in the shop manual.