1995 Chrysler LHS failing brakes

Your description screams classic rear drum brakes out-of-adjustment, but most of these cars have disc brakes on the rear. By pumping the pedal, you make the next pump before the rear shoes have a chance to fully return, so you get a bigger bite of fluid in the master cylinder. Release the pedal, and wait just a few seconds, and the shoes will retract and you'll have a low pedal again.

Try pumping the pedal up so it's solid, then hold steady pressure on it. You can try varying the amount of foot pressure, but don't release it completely. If the pedal slowly sinks to the floor, internal leakage is taking place in the master cylinder. It will have to be replaced.

Holler before replacing the master cylinder. I have a procedure that requires no bleeding at the wheels; it can all be done at the master cylinder.

caradiodoc

Leaking or disconnected vacuum line attached to brake booster that is mounted on the firewall with the brake master cylinder bolted to it. This is common with these the vacuum supplied by the factory is very under sized and barely supplies enough vacuum even when new so any cracks or leaks will cause it to no longer get the vacuum needed to assist the system they feel like they are not working and will sink quick to the floor. Same thing when power steering is lost you can steer you just need to turn steering wheel hard enough takes a lot of extra strength same thing is prob what caused your brake issue and no one else thought of it and it is a very good possibility mine waa doing the exact same thing and mine was the vacuum line right under the Cruze control module