Hi, I just bought a 98' escort as a beater car to get me to and from work. When i was inspecting it, I found that the rear brake hoses needed to be changed and so I did using Napa brake hoses + lines ( lines were rusted to hell too.) Rear brakes were then bled as well.
But afterwards, brakes seemed extremely weak and have to be pressed to the floor to even begin braking. Did not have this problem before and I had Ford journeyman helping me with the issue so I know it wasnt just me failing at installing the brake hoses / lines. Any ideas on what could be causing it would be extremely appreciated.

 

It might be a good idea to get the system pressure bled, which would elimnate any air in the system.
This sometimes happens in older cars when the system is opened for the first time (probably ever). I've seen a lot of master clyinders go bad this way.

 

Sounds to me like the master cylinder might need to be bled first then re-bleed all four wheels. After replacing brake lines there will be a lot of air in the system.