Ok, like the topic says, when I hit the brakes, the pedal slowly goes to the floor, with very little actual braking going on. if I JAM the brakes really hard and quickly, it will often get the brakes to work. It was okay at best about a week ago, but now it's pretty shot.

some info:
- car is a '90 CRX Si (so rear disk)
- I just flushed the system last week with ATE superblue and brakes were working great after that (for a few days). sequence: right rear -> left front -> left rear -> right front (which I was under the impression was the correct sequence)
- the fluid that came out was pretty nasty but the superblue was nice and clear with no bubbles in it)
- I have replaced the hose for the brake booster and the check valve seems to be doing its job fine.

what is this a sign of? My guess was booster, but some of the info I've found has said it might be the MC. Any thoughts?

Thank you very much!

 

your brake cylinder is going out...try bleeding your brakes first and inspect your brake lines...How's your brake fluid level? Any leak?

 

brake fluid is right up there where I left it after flushing the system last week. The lines looked okay (nothing out of the ordinary). the MC has some ("normal") corrosion on it and the metal clip that holds the reservoir (sp) on is rusty. Other than that, no visible leaks.

 

your master cyl is shot or you have a leak somewhere.

with the car off pump the brakes.. it will get hard.. does it go soft again? (the pedal you sickos!)

then run around the car and look for leaks.

 

ok, just went out and did some testing.

- with the car turned off, a few pumps and the brakes get nice and hard.
- I ran around and checked for leaks, nothing
- got back in the car a minute or two later, still hard.

- I turned the car on, pedal went pretty much slowly right to the floor when I pressed it
- turned the car off, pumped it back up and it got hard
- AFTER this, if I pushed relativly hard, the pedal would slowly (much slower than with the car turned on) go down to the floor.

- checked again, no leaks anywhere.

 

I have this very same problem with my DA. Im really thinking its the MC cause the vaccum hose has no signs of leaks