Brake help

[BimmerToad]

I need some help diagnosing my brake problem: I put in the 25mm 750i master cylinder into the 318is, and bled the brakes on each corner of the car in the proper order. Out on the test drive, I found that the brake pedal felt VERY soft for the first stage of travel and rock hard for the second stage, and strangely enough, the first ~2 inches of travel had no feel but substantially slowed the car down. On the way back to the garage, I found that the pads started to drag, so I took the 25mm master cylinder out and swapped in the stock MC. With the stock MC, the car felt exactly like it did with the 25mm cylinder.

The next day I was driving on the freeway and found that the front brake drag was progressively getting worse and worse, to the point that I needed to tow the car home, since I couldn't even maintain 35mph with the pedal at WOT.

Do I need to bleed the ABS separately from the rest of the brake system? How do I bleed the ABS? Has anyone else experienced this problem?

[Jordan]

sounds like you have shit in your calipers that is killing thier ability to release.

just an idea, hard to say...

[BimmerToad]

I'm going to take off the calipers tonight and see how well the pistons move in and out of the caliper. I got a hold of some rear rebuild kits, but I think I need the fronts as well. Could pad dragging come from not bleeding the ABS system?

[Jordan]

there is no "bleeding the abs system"

Its part of the whole.

[BimmerToad]

Well the calipers are fine, the master cylinder is in good shape, disabling the ABS didn't help, so I've narrowed down my possibilities to having to readjust the brake pedal.

Has anyone else had to readjust the brake pedal after installing the 750i 25mm MC? The bentley say's it's a good idea when ever replacing the master cylinder, but I haven't seen any write ups that mention it.