I purchased my ‘17 F350 July of last year. Since then, I have personally replaced the brake booster 3 times and Ford just replaced it September of this year. Well, this morning, while pulling my 40’ gooseneck, brake booster went out again. The last time I replaced the booster, I also replaced the master cylinder, because the inside bottom of the booster looked wet (maybe brake fluid).
I told Ford service that something was causing the booster to go bad. They ensured that everything tested good. I’m at a complete loss as to what is causing this. I’ve been driving over 30 years and honestly can’t remember a single brake booster going bad. Now this will be the 5th one on this truck in a year and a half.
Any help or guidance is greatly appreciated.

 

It could be that the master is the problem. Do you have hydro-boost brakes? I was just thinking that the rod in the master cylinder may be traveling to far causing a failure in the booster. Is this the stock master? That could be the problem. Sinse Ford already replaced it once let them fix it again.

 

After posting this issue on other Powerstroke forums, and doing my own research and deductive reasoning, I thought I might have narrowed it down.
I believed I narrowed it down to one of three things:
Brake Booster itself
Master Cylinder (leaking into the booster)
Or the Vacuum Pump
The pump is the only thing that hasn’t been replaced.
Ford called this afternoon and confirmed they found oil in the vacuum hose to the booster.
Parts are supposed to be in in the morning and hopefully I’ll have my truck back tomorrow afternoon.
The pump being a possibility was gained from one of the other Powerstroke forums.
There is so much information available out there as long as you don’t limit your sources.