Ok here is whats up.

89 crx dx, stock brake system.

The pedal goes to the floor and barely barely works. brakes hardly work. If you pump them they don't really get better, but they seem like they are trying.

I've bled the entire system numerous times, but it seems like there is an infinate amount of bubbles coming out. No matter how much I bleed them there are always bubbles.

I replaced the master cylinder, bench bled it, still feels the same.

The booster seems to be working. The pedal is hard when you pump it up with the car off, but when you start it it goes soft which means the brake booster is working.

Any ideas what it could be?

Is there supposed to be a gasket between the brake booster and the master cylinder? I'm pretty sure there is, but would that cause the infinate amount of air entering my system?

 

the air bubbles....?

 

sounds like youve got a leak somewhere. perhaps caliper seals.

how are you bleeding your brakes?

 

I've bled using a vaccum bleeder, and also by hand with one person pumping and another opening/closing the bleeder, using a clear tube connected to a catch can.

I came to the conclusion that the vaccum bleeder was causing all the air bubbles. Doing it by hand I didn't get them, however my brakes still feel like ******* even after bleeding for quite a while.


I concluded I do not have a seal between my master cylinder and brake booster, and I'm supposed to have one there according to the factory diagrams. Could air somehow get in the system from the back of the master cylinder?


I'm going to try bench bleeding it again tomorrow, and then redoing the whole system one last time. It honestly feels exactly like air in the system but I can't figure out where it would be coming from.

any tips or tricks for bench bleeding? maybe I'm not doing it correctly.


I do not have any leaks in the system. The pedal holds pressure just fine when the car is off, but if you start it up it drops to the floor

 

check your rear drum brakes. if the pads are not making contact you wont have any pedal pressure and they wont bleed properly.

 

all pads/shoes are in good condition and working properly.

wheel cylinders show no signs of leakage

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bambbrose &raquo;</TD></TR><TR><TD CLASS="quote">I've bled using a vaccum bleeder, and also by hand with one person pumping and another opening/closing the bleeder, using a clear tube connected to a catch can.

I came to the conclusion that the vaccum bleeder was causing all the air bubbles. Doing it by hand I didn't get them, however my brakes still feel like ******* even after bleeding for quite a while.
</TD></TR></TABLE>

yeah, vacuum bleeding does that. thats why i no longer do that, or recommend it.

stick to the two man method, best results. you can train ANYONE how to push the pedal.

here, do the test to see if your booster is ok.

 

Yes you are supposed to have a gasket between the mc and booster. When I did my swap, the gasket was just kinked a little bit and caused tons of air to get in...brakes were worthless. I took it all apart, got the gasket situated properly, bled the system, and everything was all peachy after that.