Please help! I searched and my guess is that I have a bad MC..

We're building a '90 CRX DX, and just dropped in our B18B swap. We recently swapped over front and rear disc brakes from a DA teg to our '90 CRX. We're using:

- 4040 prop valve
- Power Slot rotors
- Hawk pads up front, AEM's in the rear

We picked up a DA master cylinder/booster from the junk yard and installed everything on the car. We bench bled the master cylinder, and then proceeded to properly bleed the brakes. None of the calipers or brake lines are leaking, the brake booster is functioning how it should, and the car stops, but the brake pedal does not feel firm at all. Any clues to what my problem could be. Any info would be greatly appreciated, thank you!

Mike

 

Bump, anyone have any ideas?

 

You didn't remove the check valve from the vacuum line that goes to the booster did you?

 

Not sure what the check valve is, but I didn't remove anything during the install..here's a pic..

I apoligize for the dirtiness, we just finished the swap days ago..






Modified by MikeFabRex at 2:20 PM 7/27/2007

 

Does the pedal slowly sink to the floor when pushing on it? It helps to have the car running when u try this but it looks like thats not possible. Also, I would have just got a new master cylinder, not a junk yard piece.

 

Try adjusting the pedal, I swapped in new da crap and all new lines new calipers and still had a soft pedal. Where the booster meets the pedal try extending that push rod so you have the pedal almost engaging the booster( loosing the slap) Should make a difference.

 

Sounds like a good idea, I basically want to adjust the rod more towards the firewall correct? There's two nuts down there on that rod. One is a 12mm, which is closest to the pedal.

..closer to the firewall, there's another nut, looks like maybe a 17mm? Which one do I adjust?

The engine does run now, all vaucum lines are hooked, but we cannot drive the car, we can only idle the car. WE just received our DA throttle cable, and will be installing it tonight. When the engine is running, and you apply brake pressure, the pedal does not sink slowly, the pedal effort just feels like doo doo, as if there was air in the lines. I've been bleeding brakes on CRX's for 4 years now, but this is my first DA master cylinder swap. I'm eager to see if adjusting the pedal rod will help. Thanks again guys, please keep any ideas coming!

Mike


Modified by MikeFabRex at 4:12 PM 7/27/2007

 

You want to move it closer to the pedal. Losen the 12mm and turn it (wiht the pedal disconnected) ANd it should extend out