I have an issue with my brakes and have not been able to identify what is causing it. My brakes work first off, but when I come to a complete stop the pedal sinks to the floor. It is firm when I am moving but after I stop is when the sponginess sets in. I am not leaking fluid at all, at least that I can notice after months so I do not think that I have a slow leak somewhere. I checked the booster as per the haynes manual and it checked out ok. I completely bled the lines to ensure that there was no air in the lines. The only thing that I can think of is maybe the booster IS actually bad. I also checked the vacuum hose lines and they have no cracks in them either. Any help/recommendations is appreciated.

 

1st - Make sure there is no break fluid leaks at the calipers and rear drums. If there are replace and reblead the breaks.

2nd - If no leaks, replace master cyl. and bled breaks...

Done.

 

I agree with snobdds sounds like a worn master cylinder if you have no leaks, usually a bad booster causes a very hard pedal and reduced brake performance.