98 4x4 crazy break issues, please help
 

just bought an old 1998 blazer s10 4x4 from a guy.
drove it for a week and an annoying squeaking sound started coming from the left, rear wheel. nothing rubbing on the tire or anything, sounded more like a seized caliper. stops when you apply the breaks. not a constant squeak either, it has an even break in the sound.
I jacked it up in the driveway, took the wheel off, caliper was pretty nasty. the pads look like they have been there for years but never used, rusty, bit of rust on the rotor and maybe even a slight dip in the rotor-which might explain the on/off on/off squeaking I am getting??
the old caliper took like 2 hours to get off. it looked like the last owner put some kind of gasket sealer on the copper fitting for the flex hose. makes me wonder...
anyway I got the new caliper on real easily. but the break pads are not seating on the rotor on the back side. their just hovering over it. HOW IS THIS POSSIBLE??? the pad on the front is fine.
brand new caliper, had to order it from AMP. yes there's fluid going in there, cylinder is expanding. nothing was wrong with the flex hose fitting, other then how hard it was to get off. had to put it all back together, bleed the breaks and run into town last night and the same dam squeaking was coming out of it like before.

What the heck is going on? I need some advice before I go buy new rear rotors or spend more money on it. This has me and a couple buddies of mine totally stumped.

you should be able to manally push the brake pad into the rotor, just bolt the bracket where the pads sit in to the knuckle so the caliper can be out of the way, now slide the pads onto the bracket so they are touching the rotor. if your saying that the pad stops before it hits the rotor, can be a few things, wrong pads, wrongly machine pads from the factory (it does happen) but most likely your bracket is very rusty and needs to be cleaned, i have a small pneumatic grinder with a wire wheel i use everytime i do brakes. you have to grind down all the excess rust that has built up over the years to get the pads to slide in there properly

i see it almost daily at work, some pads are so rotted in the bracket i actually have to put the bracket in the vise and smack the pads out with a hammer, and they should move freely or with a hair of resistance

Awesome. thanks for the info. the caliper's cylinder is out all the way but the pad is still not making a connection. I'm used to working on crappy little cars, not big trucks. anyway, it turns out I need new rotors and pads all around (the rear is the worst) and I should replace the other calipers too. also it needs a break line in the back, one is leaking a little. this thing is in bad shape, its a total do over. but that's alright.
bring it!

The disc brakes on these vehicles are great... If they are maintained regularly and properly. The pads, rotors, & calipers including the brackets and hardware, needs to be replaced each time they are serviced. If you cut corners, you'll have problems... guaranteed.

The squeaking may be from the park brake shoe that is located inside the rotor, its like a drum brake but its inside the center of the rotor, chances are, the hardware is all rotted out, your park brake cables are also probably junk so if you dont plan to replace those too then you might as well just take all the park brake guts out and be done with them.

Hope this helps.

the pads travel in and out in a slotted track and there should be a stainless steel shim in that track as well
remove pads remove shim , at minimum I would gently clean the rust out of the track with a hand file
antiseize compound in the track , both sides of stainless shim and reinstall pads and caliper

Another option is the pad surface is completely contaminated with rust and will never seat , but you would see it making a mark on the rotor

Possible rust lip on rotor and or rusted out backing plates. Saying that it stops with applying brakes points to a rust lip.