Brake issue

do you have any push button switches to the left of your steering wheel? one of those is VSC, i was incorrect saying it was automatically controlled, well it is, but that switch can turn it off

 

Just fog lights and the power plug in the bed the rest are dummy switches

 

Random question but both times my booster has one this was right after a dead battery. The first time in 2016 I came out of work to a dead battery which turned out to be just a loose terminal but when I got in trying to start the pedal was rock hard. Now just recently I came out to a actual dead battery and a stiff pedal. I used my booster pack and got it started and out of no where the brakes were super touchy like barley press the pedal and brake your back. I replaced the battery and with the truck on its getting a little over 14volts but it just seems odd that both times started with a no start and rock hard pedal. I have no warning lights on and both times there was no warning before hand like the brakes felt normal and only changed after the truck was jumped.

 

OK then you do not have VSC. Random answer..no clue..low voltage makes electronics do some crazy stuff, but why the stiff pedal, makes no sense unless somehow something like a brake proportioning valve is controlled by the ECM? not that familliar with it..sorry man.

 

I always double guess myself but if brakes lock up and removing the vacuum from the booster instantly frees them I think I'll try a replacing the booster. The replacement I bought five years ago was a random rebuild by some parts yard so maybe it just went bad.

 

possibly it is internally bypassing vacuum to the backside and causing them to "lock up"

 

It's so frustrating but the last time this happened and I bought this rebuild it lasted 5 years