Changing the rear disc brakes, do i have to turn the brake pistons to get them to go in ?

Check this REMOVAL & INSTALLATION
(see Figures 1, 2 and 3 / click over images for zoom )

CAUTION Older brake pads or shoes may contain asbestos, which has been determined to be cancer causing agent. Never clean the brake surfaces with compressed air! Avoid inhaling any dust from any brake surface! When cleaning brake surfaces, use a commercially available brake cleaning fluid.

1. Remove 1 / 2 of the brake fluid from the master cylinder reservoir.
   
2. Raise and safely support the vehicle.
   
3. Remove the wheels.
   
4. Remove the cotter pin and guide pin.
   

Fig. 1: Rear disc brake components

1. Remove the caliper locating pin cover and remove the locating pin.
   
2. Swing the rear disc brake caliper away from the brake rotor and anchor plate. There is no need to remove the parking brake cable or brake hose.
   
3. Remove the inner and outer disc brake pads.

To install:

1. If installing new disc brake pads, use rear caliper piston adjuster T87P-2588-A or similar tool, to rotate the rear disc brake piston clockwise, retracting the caliper piston. This will allow room for the new brake pads.

Fig. 2: Removing the parking brake cable

Fig. 3: Use the adjuster tool to rotate the piston into the caliper

1. Install the inner and outer disc brake pads.
   
2. Swing the rear disc brake caliper back into position over the disc brake pads.
   
3. Clean the locating pin threads and apply 1 drop of a thread locking agent or similar sealer.
   
4. Apply a small amount of disc brake caliper slide grease to the shaft of the locating pin.
   
5. Reinstall the locating pin and torque to 30 ft. lbs. (41 Nm).
   
6. Reinstall the guide pin and the cotter pin.
   
7. Adjust the parking brake by operating the parking brake control several times.
   
8. Reinstall the wheel and tire assembly. Torque the lug nuts to 62 ft. lbs. (85 Nm).
   
9. Lower the vehicle.
   
10. Adjust the parking brake by operating the parking brake control several times.
    
11. Pump the brake pedal several times to achieve a good pedal before attempting to move the vehicle.
    
12. Check the brake fluid level in the master cylinder fluid reservoir and add fluid as necessary.
    
13. Road test the vehicle and check for proper brake system operation.

Hope this helps (remember to rate and comment this answer).

you need a special tool avalable at most parts stores. its a disc brake piston turning tool. you have to rotate piston clockwise while pushing in on piston. you can fabricate something that enguages the slots and push and turn till all the way in.make sure to note position of slots and put them in same place as was before or the pin on the pads wont enguage the slot

One side,turns right,and push in slightly,and the other side turns left,to retract.

Parking brake is operated by a cable and not the caliper. Your car has disc brake pads for squeezing the rotor to stop, the parking brake has drum type brake shoes that push out on the inside of the rotor. Changing the disc pads only requires squeezing the piston back in like usual.

they should screw in not compress

Raise the rear of the vehicle and make sure it is securely supported. Remove the rear wheel Remove the brake hose (A) from the suspension arm by removing the brake hose clip (B).Thoroughly clean the outside of the caliper to prevent dust and dirt from entering inside.Support the caliper with a piece of wire so that it does not hang from the brake se.
Remove the two guide rods (C) and caliper (D) from the bracket. Remove the pad shim (A) and brake pads (B).

Remove the pad retainers.
Clean the caliper thoroughly; remove any rust, and check for grooves and cracks. Check the brake disc for damage and cracks. Install the pad retainers. Check the foreign material at the pad shim (A) and the back of the pads (B). Contaminated brake discs or pads reduce stopping ability. Keep grease off the discs and pads.
Install the brake pads (B) and pad shim (A) on the caliper bracket. Install the inner pad with its wear indicator (C) facing down ward. If you are reusing the pads, always reinstall the brake pads in their original positions to prevent a momentary loss of braking efficiency. Rotate the caliper piston (A) clockwise into the cylinder, the align the cutout (B) in the piston with the tab (C) on the inner pad by turning the piston back. Lubricate the boot with rubber grease to avoid twisting the piston boot. If the piston boot is twisted, back it out so it is positioned properly.
Install the brake caliper (D). Install and torque the guide rods (E) to proper specification. Install the brake hose (F) onto the suspension arm with the brake hose clip (G). After installation, check for leaks at hose and line joints and connections, and retighten if necessary. Depress the brake pedal several times to make sure the brakes work, then test-drive. Engagement of the brake may require a greater pedal stroke immediately after the brake pads have been replaced as a set. Several applications of the brake pedal will restore the normal pedal stroke.

When I changed my sisters VW Jetta I used the follow:

1. Lug Wrench
2. Ratchet
3. Socket to fit the caliper bolts (can't remember size)
   
4. C-Clamp to push the piston back in
   
5. Bucket to set the caliper on while changing the pads

On the rear brakes I had to borrow the special tool to push in rear disc brakes from AutoZone, this tool spins the piston while pushing it back in.  Let me know if you have any other questions.  Thanks for an honest rating and thanks for using FixYa!

try screwing it in turn a set of pliers around put handle in, in the piston there are indents in the bottom

hope2help shack

The back brakes on my Honda Accord are disc brakes. After removing the brake cylinder assembly you will see the brake cylinder piston end has a slot in it. The short pin on the back side of the inner brake pad fits into this slot, but also it is used to 'Turn' (clock-wise) the piston back into the cylinder so you fit the assembly back over the new 'thicker' pads. You can not 'press' this piston back into the cylinder.