I've had the truck for two years now and it just started having some issues with the brakes. Last summer had issues with a front caliper locking up 45 mins from my house. A garage changed both front calipers and put on new rotors and pads. It blew a rear wheel cylinder to when all this was going on so it was also replaced. Now when driving in the rain/ snow i noticed it you have to panic stop the rear locks up and the front abs kicks in while the truck slows but more or less keeps going. I just missed a nice 4 pointer half a sleep on my morning commute. I'm replacing the rear drums they are about out of spec but the pads are worn but not as bad as i had hoped. I'm not sure what else i have going on , but im guessing it may not help my issue. Just wanted to see if anyone else has had any issues like this.

 

Have you had your abs speed sensors checked?

Panic stopping is bad in the first place, yes the vehicle will slow down but it will have to kill its forward momentum. In wet conditions where there is less grip this takes longer to do.

Maybe upgrading the brake pads to ones with a bit more bite may be helpful

 

you either have rear anti-lock (rears will release and fronts will lock) or 4 wheel anti-lock (all will release). It is fundamentally impossible for the back to lock up and fronts to release short of a hydraulic failure.