I can only assume that Z0, means Z06. There was not a Z06, in 97. And the brake calipers are the same for the two years.
Brake pads on a 1997 Toyota Celica are changed by removing the wheels, unbolting the calipers, and removing the old pads from the calipers. The caliper piston must be pushed in before the new pads can be installed.
Corrosion? Contaminated brake fluid?
Try replacing your brake calipers.
It's 12 mm bolts, not Allen key.
Your local parts store should be able to help / answer that question.
3/8 inch Allen
3rd Rock from the Sun - 1996 I Brake for Dick 2-18 was released on: USA: 16 March 1997
remove wheels.remove brake calipers, remove 4x4 locking hub.with special socket remove axle locking nut. brake rotor will the slide off enabling you to change bearings
1997-2004
There was no LS1 Corvette until 1997
it could be a lot of different factors such as master cylinder is leaking past seels, crack in a brake line, leaking wheels cyclinders or calipers, air in the brake system that will cause brake pedal to go to floor if it is hard and wont move could be a failed brake booster
You probably have a rusted up piston in one or more of your brake calipers. This will not let the brake piston return and release the pressure on the brake shoes. Jack the car up and turn each wheel to find the one that will not turn. Then remove and replace that caliper. If you are not mechanically inclined, you will need to get a mechanic to do this for you.