You will have to take the bleeder screw loose from the top of the caliper to get the pistons back in properly. Just take out the pistons and clean them. Then lube them well with brake fluid. Press them in with your hand in an even fashon. Do not force the pistons in. Once all of the way in, add brake fluid to the reservoir and have some one pump up the pedal and hold pressure on it while you loosen the bleeder screw a little. (Be careful not to get the fluid in your eyes.) One the fliud stops coming out, just tighten the screw and have the person in the car pump again and hold then loosen again. Do this over and over until all air is purged. (Keep an eye on the fluid level))

------------------
Benzmac:
1987 16V
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM