ok so my 00 civic hatch with b18c has a brake problem. has all stock right now and the brakes usally work fine but once in a while like 2 or 3 times in a 30 mile trip the brakes will go almost to the floor and then work but not fully only slowing down a little and if you let the petal out and press it again a couple times it will be normal again. i was told most likly master cylinder so i put in a new one and still the same. i have bleed the brakes so many times it can not be air in the lines. the pads and shoes are new and the calipers and drums are new as of last year. someone said it could be the booster but i thought the booster would let the brakes work normal just alot harder to push??? someone else said it could be the proportioning valve but does that ever go bad?? any help would be great so i can get this very bad problem fixed asap, thanks

 

any help here? booster? proportion valve? something else?

 

Bleed the system again in the correct wheel sequence. I'd recommend a One Man Bleed Tool (~$4).

 

i have bled the brakes at least 10 times now and have used a one man kit and with 2 people to make sure no air is coming out and no change any of the times, yes this was after the new master cylinder as well as before

 

Does by some chance your car idle weird? Or anything that'd indicate a vac leak around the booster line?

 

well its a new motor to me but seems like it idles fine, around 700ish and i couldnt find a leak to the booster, the one way hose is good, as far as you can blow through one way and not the other and can only go on in one direction

 

Was the master cylinder bench bled?

 

yeah master cylinder was bench bled and then the system was bled after multiple times.

 

anyone have anything else i could try?

 

If you were starting all over again, which you need to do, a spongy brake pedal is typically caused by (1) air in system, (2) bad master cylinder, and/or (3) fluid leak.