Outkast

I upgraded my pads and fluid today and cut the rotors.
They worked good before, now they suck.
What the hell happened?
I used Bonez stage I pads, and I noticed there is a large amount of brake dust on certain spots on the rims.
Could it be they need to seat and brake in? How long is it going to take, I drove around for more than an hour and the brakes still suck.
I also used Ford Motorsport high performance brake fluid. RX7.com sells it. I used it before and it works great.
I cut the rotors nice and smooth.
The pedal goes all the way to the floor like a sponge, then it eventually stops. Can't be the master. It worked perfect just before I installed the pads. Bottom line, is there like a big-*** break in period for Bonez pads, before they start working worth a shiet? Thanks

RX7Wishing

air in the line's. Re bleed

rotorbrain

i noticed mine were like that too after i bled the system. ive been thinking about doing it again with the car on so that the abs unit can get a signal. . . or something. maybe its the brakes seating in or something. . . i know they always feel like crap until theyre done seating.

paul

rynberg

1. Bleed the brakes.
2. PROPERLY bed the pads.

David Zeckhausen has great write-ups on how to do this on his vendor site:

http://www.zeckhausen.com/bleeding_brakes.htm
http://www.zeckhausen.com/bedding_in_brakes.htm

GOOFYROTOR

DIYing can be dangerous if you don't know what the hell is going on!

maxcooper

One possibility is that the master cylinder went bad during the bleeding. I had heard of this a while back, but I never had it happen to me until I changed the brakes on my daily driver about two years ago. I replaced the master cylinder and that fixed the problem.

Normally, the master cylinder only operates over a certain portion of the full range and doesn't go all the way to the floor. Junk and/or corrosion can build up on the portion of the cylinder bore that isn't wiped clean by the piston under normal operation. I suppose old fluid can increase the chances for this, since you'll get moisture in there. When you change the fluid and bleed the brakes, you do use the full stoke of the master cylinder, and the junk at the end of the stoke damages the piston seals in the master cylinder. After the seals are damaged, the pedal will be soft and go to the floor (or at least be worse than it was before). To fix the problem, you have to rebuild or replace the master cylinder.

If you did everything right and bled the brakes etc. and still ended up with a soft pedal, this may have happened to your master cylinder.

-Max

Outkast

Thank you very much for all the useful responses. I am going to study the two links and try to seat the pads, then re-bleed the lines, and if it doesn't help, replace the master. I appreciate the advice.

Mahjik

iTrader: (1)

Hey Max,

That's what happened to mine. Mine failed when I switched to track pads the night before an event. During the bleeding, it failed when I got to the FL. Actually, I was happy it failed then instead of on the track.

Unfortunately, I didn't really notice the failure until I tried to back out of the garage (and stop) at 5AM the next morning.

Outkast

Brakes have improved with wear but still not up to spec. There may be something wrong other than seating because they still suck, but they have improved. We'll see. I plan on installing braided lines and swapping the fluid again.

deepdezal1

I also changed the brake pads this past weekend, but don't have a firm pedal after I bleeded my brake system. If I pump the pedal 2-3 times, then I get pressure.

My car's brake system sound like an air is in the brake system?

Xeros

It could be you have air in the master cylinder it self. I was actually working on the same problem man. THe oddest thing is I bled my master cylinder a couple of times and at one poiont I reconnected the lines and the brake was as hard as a rock. I decided to bleed it and it got soft as **** again....

Outkast

Pads seated and now everything's normal. Thanks