I have searched all throught the archives, and couldn't find anything that came near what my problem is.

I have a 98' Civic Cx that i just bought with brake issues, when off the brakes pump up hard and hold, when running for more than 10-15 secs with out pressure applied i have no brakes, my foot hits the floor, but if i pump it up i have pressure for a little bit.

I have replaced the Master twice with ones from Junkyard, same results. I have bled the system 4-5 times, same results, even replaced a leaky caliper, same results.

Any ideas, anyone ever had the same problem??? Ive been told to check the Brake Booster, i know how to check for vacuumn from the manifold, but how do i test the booster itslef???

 

replace master with a new one and make sure you bleed it good

 

did you bench bleed the master???