I installed a Stoptech BBK today. While I was doing the stainess lines I'm pretty sure my brake fluid reservoir ran dry at one point and air got in the lines. I bled the brakes on all four corners, filling the reservoir evertime it started getting low. I thought I got out all the air, and even tapped the calipers with a rubber mallet to try and free up any air bubbles. But after getting everything all buttoned up and taking the car out to test the install, the brake pedal engagement point now seems much deeper than the stock calipers. The car will stop, but I pretty much have to bottom out the brake pedal to lock up the tires.

Questions are....

1) Is this a normal side effect of having a BBK? Possibly because more pistons / larger piston diameters require more fluid to move? Or do I still have alot of air in my lines?
2) Can the brake pedal engagement point be adjusted somehow to make the engagement point closer or the same as stock?

The car is street driveable, but I don't think I will be able to heel / toe at the track with the brake pedal as deep as it is right now. Help!

 

If you pump the brake pedal does the pedal come up? Is the pedal firm at the bottom of the stroke as it now stands?

If after pumping the pedal comes up you most likely still have air in the lines. If not it may be an issue with your master cylnder size. I had that problem in the past installing Big reds on a 93 RSA

 

Have you tried engaging ABS? The word is that if air gets into the ABS module, things like this happen. I had the same problem you are describing and engaging ABS a few times, then bleeding, solved it

 

[QUOTE=alan93rsa,Sep 3 2007, 04:12 AM]If you pump the brake pedal does the pedal come up?

 

I'd repeat the ABS --> Bleed sequence a couple more times. You can activate abs even at 10 mph if you find a sandy patch anywhere (I do it at the corner of my neighborhood street). I don't think it matters if only one wheel activates it. Bleed in the proper sequence also. Speedbleeders would make it easier if you don't already have a one person-bleeding system.

BTW, you need to bleed al lot after the ABS thing as the air is dislocated all the way back at the master cylinder/ABS modulator unit, so maybe you didn't bleed enough to move the air out the long lines?

 

Thanks. I'll give it a couple more attempts tomorrow.


Quick question on bleeding the brakes.... the service manual says start from the driver's front and work your way clockwise, but I've also heard start from the drivers rear and work counterclockwise. Will both procedures work? Is one better than the other?


A couple more notes... The reservoir was starting to get low. I topped it off and the brake light went off. The level was still about 1/4" over the MIN line.

I ran the brake booster tests and leak tests from the service manual and passed them all. I hope it's just air in the lines.

 

I do only the sequence that the manual says. It's critical not to let the fluid level go too low when bleeding, so check regularly.

 

level the BMC or make sure the rear is higher (the front is pointing upwards when the car sits level) and use gravity bleed

i dry out my BMC when i tried to comepletely changed out the stock brake fluid and i've tried numerous ways to get the padle feel back, and only this way work