Continue the brake saga....

So to continue my saga. Bad new brake booster was replaced. The 2nd one seemed to work very well. Park my truck last night, so let’s fast forward to this morning. I went to drive off and my truck brakes are locked up frontwards and backwards. Thoughts??
Thanks again.....

 

this don't sound good

 

Can you pull the vacuum hose off the booster and see if the brakes unlock?
Make sure the parking brake is ON, and in park. When the hose is disconnected the brakes will be much harder to apply.
Have you confirmed that it’s all wheels locked up?
And is the parking brake on? (I know, I have to ask)

 

There may also be a check valve in the vacuum hose to the booster.
You might as well check it if you Pull the vacuum line?

Also, is this a 4.0 or 2.7?