I've got a weird brake problem. When i step on the brake pedal when im driving, itll feel nice and firm, but after i drive around for a while, if i sit at a stop light and have my foot on the brake, the pedal slowly sinks to the floor. It sinks faster when the A/C is on also...

 

Sounds like your MC is going out. There's a test in the Helms to see if it is the MC, but I don't remember it right now.
I know it's been asked before, so you can also do a search.

 

Yeah, I have the same exact thing. I asked around and I was told that it is a seal in the MC that is letting fluid seep through a little or something to that effect. It does stop the car fine but constant pressure for a long time will allow the pedal to drop. I have to sit at lights with the ebrake on.

Probably need to replace the MC but I am saving for the ZC...priorities But I'm looking for a rebuilt MC to put in as soon as the motor is in...at least it stops the car....

 

i agree with the rest of them... had the same problem about 2 months ago... i changed the pads, rotors, and the calipers and still had the problem until i changed the MC...

 

Thanks guys. I been asking around (not on Honda-tech) n i keep getting mixed answers. People have been telling me its my brake booster, faulty brake lines, even telling me to get steal braided lines But yea, crap ive been wanting to fix it but i been saving for my ZC

 

Yeah mine did the same thing. I replaced it with an Integra one. Whenever I get the brakes on my car working again I will let you know .

 

if it is leaking MOST of the time you will see that below the master on the booster it is damp/wet...check and see.

 

from what i've been told, if the pedal only sinks with the car on, then its the booster (since its vacuum driven). if it happens if the car is on or off, then its the MC.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by essex &raquo;</TD></TR><TR><TD CLASS="quote">if it is leaking MOST of the time you will see that below the master on the booster it is damp/wet...check and see.</TD></TR></TABLE>

Actually its not leaking, the brake fluid level is still at the full mark. I guess its just by passing a seal or something, or like the other guy said, might be a vacuum leak in the booster

 

I doubt its a booster...most likely your master or a poor bleed job.

 

I had the same thing happen to me a couple of weeks ago and it just got worse by the day. It actually got to the point to where I had to pump the brakes to stop. I replaced the mc and bleed the brakes and they work great now. I also heard that if it is the brake booster the pedal will be really hard to push down ( because they assist u in braking) but I don't know for sure.