spoungy brakes, bad master cylynder?

[kevs250]

recently I changed my front brakes, i have a 70 F250 with front discs. before and after i changed the brake, the pedal was spoungy and i was able to press the pedal to the floor and still not stop, and bleeding the brakes didnt help either. soo my guess would be the master cylynder.
soo if you guys could give me some input, that would be awsome

[Creecher88]

It could be either the master cylinder or a leaky line. Make sure to check the line to make sure. They may be wanting to stick, maybe try to clean the master cylinder out.

[bugser]

I could pump mine for awhile, then it slowly sank to the floor. Not all at once, just a little closer every day. Then one day when I got to work......


Fortunately I have AAA.

[basketcase0302]

kev,

before and after i changed the brake, the pedal was spoungy and i was able to press the pedal to the floor and still not stop

I would agree with James...this usually is a sign of air in the hydraulics of the brake system.
Get a "Mityvac" tool and start from the farthest wheel and bleed the lines again.

Basketcase

[Wes]

I'm going to say if not external leak your master is by passing and needs to be replaced.

[FLATBEDFORD]

How about bad rubber lines. Haven't I read here that when they get old, they can flex under the pressure and make the brakes feel soft?

[kevs250]

ive checked for leaks in the lines but i found all the lines to be in OK condition, and like james was saying, i pump up the pedal and build pressure but when im stopped at a light the presure in the pedal starts to slowly go down and the pedal sinks to the floor. soo I think Im goin to replace the master.