1992 Saab 900 how do i push the calipar piston back in on t

You have to remove the brake cable first before you can remove the plug. You just need to pull the end of the brake cable out of the slot (blue circle).

Hello .. thanks for the donation .. much appreciated Hope this helps .. let me know Removal & Installation (900 Series) Raise and support vehicle. Remove wheels. Disconnect parking brake cable at caliper. Remove plug from adjuster screw. Loosen adjuster screw. Pinch off brake hose. Loosen brake hose. Plug openings. Remove dust covers and guide pin bolts. Remove caliper assembly and brake pads. Rotate caliper to unscrew brake hose. To install caliper, reverse removal procedure. Tighten bolts to specification. Bleed system. Pump brake pedal several times to position brake pads. Adjust parking brake. See PARKING BRAKE under ADJUSTMENTS. PARKING BRAKE NOTE:If installing new cable(s), apply parking brake several times to stretch cable(s). 900 Series Lift rear seat. Using a screwdriver, pry adjuster apart. Insert .08" (2.0 mm) feeler gauge between brake lever and stop on brake caliper. Rotate lock nut against adjuster sleeve until feeler gauge drops out. Apply and release parking brake several times to settle adjuster. Ensure clearance between brake lever and stop is .02-.08" (.5-2.0 mm).