put pressure on the piston(c-clamp works good). If it doesn't push in petty easy, then open bleeder. if that doesn't work, replace calliper. if that did work, replace brake hose.
How to change brake lines on a 1991 Buick Lesabre?
Check your brakes and rotors. Most likely the brakes are locked up and some of the time the pistons in the calliper's will freeze up also. I had the same problem, just replaced brake pads, callipers, and rotors and its all good.
Dot 3
Small pedal on the left of the brake pedal - activates the rear brake to hold vehicle
press back down on the pedal
Cut the wire
Should have an access panel inside trunk
carb cleaner or brake parts cleaner
5/16" allen
33 Ft lbs
You may have a vacuum leak at the brake booster. Have the brake booster inspected.
Book time for replacing brake booster 2.6 hrs