2005 E-150, recently experienced spongy brake pedal, pedal requires several pumps before the brakes firm up to stop, once at a complete stop with a somewhat firm pedal, the pedal will slowly almost go the floor (very similar to the sensation when bleeding the brakes) once you pump them up again they are okay. Absolutely no fluid loss anywhere, so I replaced the master cylinder, then bleed the brakes. I am all set to pat myself on the back for another job well done, but when I go for a test drive the same symptoms re-occur. I bleed the brakes again but with no change. I consult my Friend (ford Mechanic) who advises that the 2000ish E150's had problems with expanding brake hoses (defective hoses but did not include 2005 models), also that the van would pull to one side or the other depending on the defective hose side. BUT my Van stops straight with no hands on the wheel.

Also, the firmness of the pedal seems to vary at times, also sometimes it will go to the floor at a stoplight, others not, I am ready to change hoses but I am hesitant to do so without some test to prove they are faulty, But I really would like to consult with anyone who has experienced these symptoms before and has a successful fix, thanks in advance for your assistance!

 

This sounds as much like a defective master cylinder or one not properly bench bled before it was connected to the rest of the brake system.

Flexible brake lines can and do fail regardless of year although its safer to say the older parts would be most prone to this. I'm not sure I'd put any faith in saying something like 2004 parts could be defective but 2005 not.

Either way you've got air in your system that needs to be addressed. If you've used a discounted brand of brake parts that could also be an issue.

 

Could be the hose at the rearend that's expanding. A careful inspection of these hoses is in order here. Get a friend to operate the brake pedal while you watch them as he operates the pedal.

 

Master cylinder is dying