i have replaced the brake caliber on driver side cus it wouldn't release all the way and now it seems like the new one is doing same thing. And when i hit my brakes the truck pulls hard to the left. i checked to make sure the passenger side works and it does but it doesn't grab as soon as u hit the brakes. that's how i found out the driver side was holding after releasing the brake. maybe i need new lines? or flush the system? i dont know i need help cus its dangerous when i need to slam on brakes and it damn near throws the truck in the ditch.

 

take the wheel off, and have someone hit the brakes, when the caliper sticks, open the bleeder and see if it releases, if it does, you most likely have a bad rubber brake hose on that side. I usually replace calipers and rubber hoses in pairs, that way everything is even side to side. sometimes you get lucky just replacing one, but a lot of times if you dont replace both sides you still end up with a pull to one side

 

change out the rubber lines i had the same issue with my truck after i replaced the rubber it was fine!!

 

by what your describing, there is air in the line to the pass side caliper, the air will compress the engage the caliper slower that the other side wich is working as designed as you described, it is not a bad idea to replace the lines along with calipers but in my exsperience its hardly neccesary, calipers die a slow death by corrosion from the piston being in a extended position for extended periods or even worse by interior corrosion dur to the hydroscopic propertys of brake fluid,
A regular scheduled brake fluid flush is something ppl ignore usually until after its to late, and it literally eats your system from the inside out with corrosion, I test every vehicle that comes across my rack but rarely ppl pay attn to my notes

another thing i almost forgot, verify the condition of you pads because thickness variation can also cause delayed engagement , probably one of the more common problems usually caused by pads binding in the hangers due to corrosion

good luck