I am new to this but my proublem is no pwr brakes but if i drive a ways i have one time use of the brakes before i have no brakes again i have changed the pwr booster and the master brake cylinder and i seem to have vaccum what else could it be.
Please help

 

Welcome aboard!
Did you bleed the system out? Could have air in it.

 

Yes i have bleed the system and am sure there is no air in system i am thinking that the vaccum pump may be bad but it seems to have plenty of vaccum i have no way of checking it or know what the vaccume should be.
thanks
Nick

 

Does the pedal feel firm when yo ustep on it or does it go to the floor?

 

Yes the pedal seems firm like i lost my pwr brakes i can barly stop the truck but when a drive about a cauple 100 feet they work again once then they go firm again.

 

Sounds like it is a vacuum issue...i don't know what to tell you though, maybe someone else will chime in.

 

Hey Nick, did you ever get your brakes figured out?

 

does your heater vents work, can you select floor or defrost, my power stroke vacuum pump went out and i had no power brakes and the heater vents were stuck on defrost, that is one way u can tell if u lost vacuum bc the blend doors work off of vacuum

 

How is your power steering? Are you loosing Break fluid?

 

Hey I had them same problem replace the vacum pump, rebuilt at Auto Zone 99.00.
That will fix the no power brake problem!