1993 cutlass weak brakes

Hi everyone….I have problem with brakes on my 1993 cutlass DOHC 3.4 l engine. The car went to three different mechanics ( including dealer ) and still do not have sufficient brakes . It is unsafe to drive. The pedal is hard and travels one 1 inch. Seems like weak boost. Vacuum checked Ok , check valve Ok, new booster . Third master cylinder (used) I was told that the calipers were inspected and new rotors and brake pads were installed.

This sounds like you have a blockage in the system somewhere. You may have to remove every brake line and blow them out or replace the lines to the brakes. If the fluid is not moving to the brakes that will cause the feel you describe as it is not leaving the master cylinder causing the firm pedal. If you have abs then the problem is probably with the abs system not working correctly.

Do the troublesome rear brakes work, very common for the rear caliper slider pins to freeze up and no movement of the calipers results in poor stopping and a firm pedal.

Thanks I was suspecting that there are some seized components or blockage in the system .