Can you do damage compressing the calipers while working on brakes? How do you relieve the pressure before starting work?
My mechanic compressed the calipers to remove to lube the sliders. Now brake pedal is hard but stopping requires more pedal pressure. Can you do damage by compressing? If so can it be corrected?
sounds like the brake booster has failed. Compressing the piston in the caliper is normal practice with brake jobs, the only damage that can occur is fluid leaking and will make your pedal sink to the floor.