I can't get the caliper cylinder to depress. I have tried using a c clamp but it still won't depress. It is the rear brakes of a 95 ford taurus. Could it be the screw in type?

The pistons in the caliper should retract without much effort. A "C" clamp is usually all you need to do it. I suspect you have a seized caliper or possibly a kinked or crushed brake line (preventing the brake fluid from returning to the master cylinder when the piston is depressed) feeding that caliper - but isn't very likely.

Open bleeder valve & push caliper piston, in as
you rotate piston to screw in parking brake

Do this by hand,only use a clamp on the front calipers

You will have to use a c-clamp or brake piston compressing tool to get that piston back in, while you have the brake master cylinder fluid reservoir cap off.

you should'nt have any tension on the parking brake,unless it's on. check the parking brake to insure that it's in the off position. chock" the rear wheels,to make sure the car does'nt roll while you're jacking it up and "always use jackstands,do not trust your jack" does your brake caliper piston have a + on it?it will be on the brake caliper piston itself, if so,then you need to back the brake caliper piston back in by turning it counterclockwise,auto parts stores sell a special tool to back the brake calipers back into place, i've always used a straight screwdriver,to turn the piston counterclockwise some do turn clockwise though to retract the brake piston. a simple call to the auto parts store where you're purchasing the brakes will tell you which way the piston will need to be retracted.other wise,it's a simple brake replacement,just push the brake caliper cylinder with a "C" clamp to retract the brake caliper, also,if you are replacing brake rotors,purchase the brake kleen to spray on the new brake rotors when you replace those.they have a clear film on them,you'll need to remove that film to insure no future issues with the brake rotors.simply spray the front and back of the brake rotors with this spray to remove the protective "film"and as always,thank you,for choosing fixya.com!

The easiest way is to:
open the bleeder nut
use a C-Clamp to depress the caliper so you can slide in your brake pads. ;-)

get ur self a clamp to depress the brake cylinder back in.. jack up car..
remove tyre
the brake should be held in with two double bolts
a 17 and a 15 mm maybe..
loosen the botton one
remove the top one
the caliper should just slide off the disk now in an arc
remove old shoes
using the clamp tighten it up to depress the cylinder back into the caliper..
replace shoes
slide caliper back on disk
bolt nice and tight back into place
replace trye
and away ya go
i find bleeding to messy for the clamp works fine
good luck

The pistons in all calipers I have seen can be forced back into their seat to allow new brake pads to clear. If constructed as most, a C-clamp can be used to press the cylinder back in.

If it does not push back with a c-clamp,then it will turn to go back in,the right side,and the left side will turn either left,or right hand to go back in,depending on witch side you are working on.

Too extensive to explain and diagram here; however,
Go to the "Reference Section" at your local public library.
Find the Chilton's or Motor's manual for the 1998 Ford.
Photocopy the pages you need using the public copy machines (10 ~ 20 cents per page).
You will need a large C Clamp in order to compress the brake caliper piston back into the wheel cylinder. Remove some of the brake fluid from the master cylinder; the fluid will "back-up" into the master cylinder reservoir when you compress the caliper piston.
Only two long bolts hold the floating caliper in place.

There is a tool that you can buy or rent at the parts house that you can connect to a hand tool EG: 3/8 rachet to use with a tool to compress the caliper while you turn the rachet. You will see some raised teeth on the calliper piston for the tool to bite on. Since the rear brake is used to lock the parking brake it has to have a self adjust to compensate for the brake pad wear. EG: Old school drum brakes adjust when you back up depressing the brakes and letting off while the vehicle is rolling allows for the adjuster to reset the brake shoe clearance.