BPOHIO, When you push on the brake pedal, take a look at the hoses, do they swell at all? When the pedal is released, do they collapse? A collapsed hose will hold the piston from returning, in essence,a stuck piston.
Your dealer may also have old stock, with dried seals.
Also, pads and calipers should come with new sliders. It is imperative to remove the sliders and scrape the rust out from underneath (as Clockworkorange said previously).
I live in NH and have to pull the sliders apart on an annual basis to keep them free, on my 02 KJ, 05 KJ, and 01 Grand Marq.
05 Liberty Rocky Mtn. 05 Suzuki DR 650