brake aren't working right. first brake application when stopped or driving worked properly. second application brake pedal gets really hard with little response. replaced master cyclinder no change to braking. bled the brakes farthest to nearest. no change in braking. checked vaccum pump. appears to be good. can brake booster have a slow leak? how can i properly check the booster to see if this is the problem? any other suggestions?

 

Still sounds like a bad booster.

 

not a bad booster. bad vacuum pump. your vacuum pump is not working properly. had this happen, that is how i know. same exact thing

 

thanks for the help.