Trying to replace rear rotors and brake pads, caliper will not retract enough to fit new pads and rotor. it will not retract at all actually. even when applying force

One or both of the brake callpers are not releasing when you release pressure on the brake pedal so you have continued contact between the brake pads and the brake rotor. This will overheat the brake pads and rotors and produce a burning smell and smoke.

If your brakes were working fine before the people you used to fit the new pads and rotors got hold of your car then the most likely cause will be faulty installation. For example if the inner and outer brake pads have been reversed when fitted in the brake caliper this will cause your brakes to bind up as you have described. If the brake caliper slides have not been properly lubricated with the correct product (or not lubricated at all) the calipers can bind up and hold the pads on the brake rotor.

In your case I would suspect the new brake pads have probably been reversed during installation and that is what I would be looking at first. But there are other possibilities that may also need to be checked.

You can take the vehicle back to whoever did the sloppy work and get them to fix it or take it to a competent mechanic very close to home who can check over the installation work. (Those that did the work should have road tested the car before giving it back to you and binding brakes should have been noticed if they were half competent). You don't want to be driving far when your brakes are like this.

2. Your brakes can also bind up as you have described if there is a blockage in one or both of the flexible brake hoses connected to the brake caliper. Usually you won't get two at once though. When this happens the blockage in the line will not allow the brake fluid to flow back up the lines when you release the brakes (and there is no pressure pushing it back) so the brake pads will not release from the brake rotor. The flexible brake lines need to be replaced every 7 -8 years or so as they deteriorate badly from the inside but outside they may look just fine. If one or more of your flexible brake lines were bad before you replaced the brake pads and rotors then fitting the new pads and rotors will really show up the problem.

3. You can also have a brake binding problem if the piston in one or more of your brake calipers is corroded and will not retract back into the bore when brake pressure is released. The piston or pistons in the calipers press on the back of the brake pad unit and force the pad onto the brake rotor. If the pistons are corroded (which will often be the case in old calipers) they can bind up in the caliper bore and not retract back into the bore when the brake pressure is released. If you had this problem before the new pads and rotors were fitted the problem will show up much more now that new pads have been fitted. It is a simple task to check if any of the pistons in any of the brake calipers in your car are binding up and not retracting as it is any of the installation work that has been done.

Some businesses will do very sloppy brake work and not check that everything is freely moving correctly when the brake pedal is applied and released as you need to when replacing brake pads.

Depending on vehicle. Find level ground and park there. Put chocks in front and behind wheels not being lifted. Loosen lugs, jack up vehicle, set jack stands, lower vehicle on jack stands, remove lugs and wheel. Open hood remove brake fluid cap. Remove two bolts holding caliper, pull caliper off rotor disc and bracket, remove pads, place a used pad in front of caliper piston, use a c clamp to push caliper piston in caliper, remove c clamp and old pad, hang caliper up, remove 2 bolts holding caliper bracket, remove bracket, remove rotor, install new rotor, install caliper bracket, install new pads, install caliper, repeat this on other side, put cap back on brake fluid tank, remove bleeder fittings and keep pressing brake pedal until an even flow of brake fluid sprays out. Install bleeder fitting. Make sure brake fluid doesnt get on paint and is contained and disposed of correctly, top off fluid install wheels and raise car up remove jack stands, lower car and break in new pads

did you turn the rotors some times there ia ridge on the rotors that needs to be machined down.

Hi, if this is a front caliper that is still on the rotor, I pry between the rotor and rear brake pad to push the piston in. I usually have to pull on the caliper a bit to get it retracted enough to get a screwdriver in between. If the caliper is already off the rotor, I leave the old inside pad on the piston and put a large c-clamp over the caliper to push on the pad and retract the piston. If this is a rear disk caliper or if you have any questions, please reply.

2 ways:

1. If caliper is still on rotor, use a small scewdriver to gently pry between the rotor and rear pad. Once loose, use a larger screwdrive, but continue to pry gently and slowly until fully compressed.

2. Caliper off rotor. Put back pad in place and apply a c-clamp across pad to back of caliper. Slowly close clamp until piston is fully retracted.

OK?

Normally, unless the caliper is not functioning or leaking brake fluid you don't have to replace it.
Replace the rotors and pads only.

Rear disc brake pads offer better performance and are not as affected by moisture like conventional brake shoe style brakes are. Rear disc brakes are similar to front disc brakes. The main difference is that rear disc brake systems must incorporate the emergency brake system. There are two methods widely used for the emergency brake with rear disc systems. The first system is a brake shoe inside the brake disc that is actuated by the emergency brake lever. The second is a screw style actuator inside the brake caliper. When activated the brake pads are forced into the brake disc and held tightly by the emergency brake lever.
READ COMPLETELY BEFORE STARTING
Step 1 - Identify Rear Disc Brake Components
Rear disc brake assembly includes; rear brake disc, rear brake pads, brake caliper mount and a caliper mounting screw. (Note: Some vehicles do not have the rotor mounting screw.)
Step 2 - Removing the Rear Brake Caliper Mount Bolts
To replace rear brake pads and rotors the rear brake caliper needs to be removed. First loosen the rear brake caliper mount bolts and remove them. Turn counter clockwise.
Step 3 - Lift Rear Brake Caliper from The Caliper Mount
After the caliper mount bolts have been removed, gently lift the brake caliper from the caliper mount. Inspect the caliper slides; they should move freely in the caliper mount. Remove rear brake pads and hardware.

Step 4 - Removing Caliper Mount Bolts
With a socket wrench or other appropriate removal tool, loosen the rear brake caliper mounting bolts. Remove bolts and lift the caliper mount and remove it from the vehicle. Remove the retaining screw from the disc mounting hole. Tap the rotor gently to release any rust that has accumulated between the rotor and bearing hub. Lift brake rotor from wheel hub holding on tightly, using both hands. You do not want to drop the rotor.

Step 5 - Removing Rear Brake Rotor
Remove the retaining screw from the disc mounting hole, tap the rotor gently to release any rust that has accumulated between the rotor and bearing hub. Lift brake rotor from wheel hub, hold on using both hands and do not drop.

Step 6 - Install New Brake Rotor
Check the new rotor against the old brake rotor to make sure they are the same size. Clean the mating surface on the wheel hub before the new brake rotor is installed. Reinstall rotor retainer screw.
Step 7 - Reset Rear Brake Caliper
Before new brake pads can be installed, the rear brake caliper must be reset. The reset tool winds the piston back into position so the new brake pads will fit. This style of brake caliper will not compress with a clamp tool; it can only be reset with the proper reset tool.
Step 8 - Reinstall Rear Caliper Mount and Install New Rear Brake Pads
After the caliper has been reset, reinstall caliper mounting bolts and make sure the bolts are tight. Then match up the old brake pads to the new brake pads. They should be exactly the same except, of course; the old ones will be worn out. Check the new brake pads for proper fit and install any brake hardware that is required.
Step 9 - Remount Rear Brake Caliper
Reinstall the brake caliper, align brake pad hardware and reinstall caliper mounting bolts. (Note: align the rear peg of the brake pad to the groove in the caliper piston.) Recheck and retighten all caliper and caliper mount bolts. Bleed brake system to relieve any air in the system. Before driving the vehicle, push the brake pedal down and let it up slowly. This operation forces the brake pads to travel to the brake rotors. DO NOT DRIVE VEHICLE until proper brake pedal operation resumes. When test driving vehicle listen for any unusual noises during the operation of the brakes.
WARNING! Always have the vehicle under inspection on level ground, in park with the emergency brake on. Always wear protective eyewear, gloves and necessary clothing before inspection or work begins. Never crank an engine over when anyone is near the battery or engine. Always have an operational fire extinguisher close by, obey all first aid instructions in the event of an injury. Never stand in front or behind a vehicle when cranked over or running. When engine is cranked over keep hands and clothing away from rotating components. Never move a car without proper brake pedal operation.

Squeeze the pistons with large pliere to get a little more clearance

Try tapping around the rotor hat (the area that actually fits over the hub, where the lug bolt holes are) with a hammer. That usually will loosen up a rotor that's stuck due to heat, dust, etc. As for compressing the rear piston, they're a screw-in design, not a compression design like the front calipers. You need a piston retracting set (you can borrow them from AutoZone), and with that you can screw the pistons into the calipers. After removing the reservoir cap underhood, screw them all the way in so that you have ample clearance for the new pads over the new rotors, then pump the brakes a few times before you hit the road (put the reservoir cap back on first).

A big pair of channel locks will collaspe the caliper but it does take some muscle or you can release the brake line nut and releave the pressure but then you would have to bleed the brakes.