My front brake get tight, I have to really accelerate to get it moving. I replaced the master cylinder reservoir, it seems to be leaking a little bit. My brake petal usually is soft, i have bled them many times but they are still soft. I also replaced the front calipers and brakes, they are still tight, but at random times the front will stop rubbing.

 

One sneaky cause of brake rub is worn out flexible hoses. The inside of the hose collapses and retains pressure against the brake. I had this problem on a car... after replacing calipers it still rubbed. New flex hoses fixed it. How old are your hoses?

 

I don't know Ive only had the truck for a year or so and I haven't messed with them