[Chartreux3]

I been working on my e92 335i brake system and am flustered and in need of some advice. I got everything I needed to update my brakes as they were original with 56k on them. New pads, rotors, brake censors and a G2 paint job. After each corner of pads installed I pumped the brakes a few tiimes to keep the resovoir in check. Maybe I pumped the brake to much as the last pads I had to install on the drivers rear looked as if I pushed the piston out to far. Some brake fluid must of leaked from it somewhere. After I cleaned up a small amount of brake fluid I compressed the piston, installed the pads pumped brakes. The problem is the brake pedal is almost dead and I get a triangle with an ! on the dash. Driving the car on the road it dont have much stopping power and the brakes dont do much untill close to the floor. I looked for leaks especially on the driver rear but all looks good and all the rotors look to have similar wear.

[ken518]

If fluid leaked out, you may have introduced air into the system which explains the dead pedal. Even a small amount of air can cause the pedal to feel very soft. I would try bleeding the entire system.

[TC Kline Racing]

Originally Posted by ken518

If fluid leaked out, you may have introduced air into the system which explains the dead pedal. Even a small amount of air can cause the pedal to feel very soft. I would try bleeding the entire system.

This ^^ When you were pushing the pistons back to put in the new pads, did you open the cap to the master cylinder? (you should have).

It is typically recommended to bleed the brakes after you install new pads at all corners. When you push the pistons back into the caliper, it can sometimes cavitate or suction air into the system.

I would start with bleeding the brakes, and then let us know if that fixes it (it probably will) unless you have a leak somewhere.

[Chartreux3]

Thanks for the replies I think everything is working as intended now. Took the car to my local mechanic and I suggested flushing the system. After checking things out they pushed all pistons back and did a full vacuum bleed. There was a small amount of air that came out the driver rear. Im not sure what the best way to do things are when doing all 4 corners. Pumping the brake inbetween pad installs is what I think caused me the problem with overextending the piston and getting air in the line. I had to line up the piston cylinder to compress it back as it popped out and spit fluid.

[TC Kline Racing]

Originally Posted by Chartreux3

Thanks for the replies I think everything is working as intended now. Took the car to my local mechanic and I suggested flushing the system. After checking things out they pushed all pistons back and did a full vacuum bleed. There was a small amount of air that came out the driver rear. Im not sure what the best way to do things are when doing all 4 corners. Pumping the brake inbetween pad installs is what I think caused me the problem with overextending the piston and getting air in the line. I had to line up the piston cylinder to compress it back as it popped out and spit fluid.

Oh, I didn't know the piston popped out all the way, you ABSOLUTELY got air in the system that way....maybe I misread your first post.

In the future, do not pump the brakes at all, until you are done with all of them, and always start at the corner furthest from the master cylinder and work your way closer.

Glad you got it fixed.