Brake Pedal Too Hard To Press!!!

[biglu7744]

-1996 f-250 4wd- ... I need anyone's help asap, im new to this and could appreciate any help! i will try and explain my problem as simple as possible, and by the way i just changed my vacuum pump today and yesterday i bled my brakes, there were no leaks at any wheel nor around my master cylinder etc.... Ill be driving down the road and the first pump i give my brake pedal is fine but if i continue pumping the pedal while im slowing down it gets REALLY firm till the point that i can barely press it anymore and it takes a good second for the truck to finally stop, and while the pedal is really firm my brake indicator light comes on. But once i leave the pedal alone for a good 5 seconds or so, the pressure built up will finally decrease and the indicator light will turn off. Im thinking it could possibly be the brake booster or master cylinder??? ... i thought by changing my vaccum pump it was going to fix my problem but it didnt so now i need some advice please!

[RUSTY OBS]

I'd go with break booster buddy!

[1Dieselman]

I would check for vacuum leaks. Check the vacuum manifold that is on the drivers inner fender. If you have one hook up a vacuum gauge there, just because the vacuum pump is new doesn't guarantee anything but it really sounds like you have a serious leak

[biglu7744]

ok i appreciate it guys! .. do you have any idea whatnumbers i should be looking at when i hook up a vacuum gauge?

[1Dieselman]

No I'm not real sure but I would guess at least 20"

[biglu7744]

Will try this tomorrow after i get the gauge!

[flatland freak]

i believe it should be close to 25 inches of vacuum