On my GMC Sonoma SLS (4x4), I have two pistons on the brake Caliper and can not get them to seat equally flush. At the best I can get about 1/4 inch sticking out. Is this normal or am I missing a step? Thank You in advance :)

the caliper has two slides that have a "shoulder" to cry on...er um to purchase and square up...seen it where the careless installer cross- threaded the pins leading to uneven front to backside wear....I'd start by checkin' the amount of squish....you shoud be able to force the fluid back upstream and create the wiggle room that you can test the smoothness of the slides....disassemble, clean and use dilectric grease (white grease) on them....check the smoothness of operation...replace the caliper if the piston is stickin'~....that would cause uneven braking and be immediately obvious~

is there uneven pad wear (inside and outside)?~definitively would look at the ease of slides...you know they are supposed to "stick out" and have a rubber boot protectin' the slide....okay~?

if you're re-using the old disc rotors the wear is gonna be a little uneven, but if the slide is sticking will be mostly worn that one side~

Jim....it's been a while, forgot about the clamp....I've Giant c-clamp in my box I'd use just for this....also the hydraulic piston pusher that cradles inside the casting....got one of those too...use it for a steering wheel puller mostly with two added clearance holes~