94 Plymouth Grand Voyager brake problems

Last week I had new ball joints and brake pads put on the front of my '94 Plymouth Grand Voyager and everything was fine...until today that is...I had to stop hard and fast and when I did, I heard a loud pop sound and then my brake pedal went to the floor and I skidded before I came to a complete stop...thankfully, there was no accident caused by this...I SLOWLY made my way home, which luckily enough was only a few streets over. There is no sign of fluid leaking even when pumping the brakes and the fluid is full. The pedal seems to no longer be under pressure...any ideas before I go buy several different parts to find that they aren't the right ones? Thanks in advance! I just got it inspected!

I assume the pedal still goes to the floor? Brake warning light on? If so, you are losing hydraulic pressure, either externally (leakage) or internally (master cylinder). Rule out all external leaks first.

There were no leaks but it was a brake line! Thanks!