problem with brakes

I have a 95' Nissan Altima with 125k miles on it. I had both front brakes replaced probably about 10k miles ago (don't remember the cost) so both front wheels have new calipers, brake pads and rotors. I think it may be about time to get new rear brakes. I don't know if the rear brake assemblies are original or not but here is the problem... It seems as though the left rear caliper has frozen. That left rear brake assembly has just started to make a screaching sound and is louder when driving in reverse. I took the tire off and tried turning the rotor in both directions and it is a bit tough to turn and makes that screaching sound (louder when turned clockwise or reverse). It doesnt look like the pads are worn out and the sound is not a metal on metal sound that you get when that little metal piece rubs against the rotor. The rotor has a good amount of rust along the edges and is definately quite a bit worn down were the pads touch it. So my questions to you guys are...

1. Is it common for calipers to freeze up like this and can anything can be adjusted or should I just replace the caliper, rotor and pads?

2. The right rear brake assembly is a bit beat up too so should I have both both rear brakes replaced?

3. Could I do this stuff myself (I have mediocre knowledge of cars and decent hands-on skills)?

4. Whats an estimated price to change the rear brakes?

Maybe your park brake cables are binding. Inspect them to make sure they slide without sticking. Replacing calipers and rotors is not difficult. Search for prices on the internet. Loaded calipers means they come with new pads. Don't buy rotors that are cross-drilled.

http://www.rockauto.com/

http://www.autozone.com/

The car is an automatic and I only use the parking brake maybe once a week for only when I'm parked on a hill. Does it still sound like it could be the problem? Braking is not a problem as the car brakes with good force and in a straight line just that it has the sound thats alot louder when driving in reverse or applying the brake. The sound is like a squeeling sound caused by vibration or something.

Is there suppose to be a thin layer of air between the brake pad and rotor when the brake is not applied? Seeing as how the pad was rubbing up against the rotor when I had the wheel off I would guess its a frozen caliper right?

Brake pads touch the rotor very lightly under most circumstances. There are always high spots on pads and rotors as well as rotor runout which cause the pads to touch the rotor. It is normal to hear noise and feel some drag when you turn the tire and wheel. You will probably see where the rubbing and noise is coming from when you remove the calipers and inspect your used parts. Your park brake cables may be fine. Do you want to risk your purchase and effort to replace calipers and rotors only to discover later that one or more cables are the cause of excessive dragging and noise? You may have a caliper that has corroded inside and swelled the seal causing it to bind. You need to inspect and determine the cause on your vehicle. Layer of air... over most of the pad, maybe, not able to see or measure such little thinness. Not really a factor to consider. Does that make sense? Hydraulic brake hoses can also swell closed on the inside. Stepping on the brake pedal can force fluid into the caliper through a restricted hose, yet restricts the fluid from returning and allowing the caliper to completely relax when the brake pedal is released.

I bought calipers, rotors, and pads for the rear wheels today all for $250. Installed them and everythings working great. Thanks for the help

Wanted to ask for some help with back brakes on my 1995 GXE 5-Spd .
Replaced front disk pads with no problem. Went to check the back brakes by 1st removing the drum, but it would not come off. In the center of the drum there is a nut/coter pin in place, which I beleive secures the bearings. Can't tell if that assembly is also holding the drum in place. Would like to avoide removing this nut/coter pin if it's not necessary. Can anyone give me some help? Thanks

my car has 4 wheel disc brakes and thats the first time I have done it myself so I have no idea what to do with drum brakes.