You may have sticking caliper slides, or a set of junk brake pads glazing over and sticking to the disc, You cannot grease the caliper piston, but can grease the slides. No you cannot adjust the pressure in the lines, and depending on the condition of your brakes you may need calipers, and brake lines. A bad master cylinder will do the same thing as a brake hose that is restricted---- wont allow fluid to flow back when the brake pedal is released.

Mkae sure there is sopme grease on the caliper slides or they will stick. Also make sure you place a small bit of grease on the side of the pads where they slide in the caliper housing. This is a common issue with disc pads

Thanks!that seems like a good solution.i think im going to try to grease the slides and get new pads before i get new calipers.