I searched the archives, but would like some detail. Just did the BMW front upgrade. After using my pressure bleeder set at 10 psi and going thru a liter of fluid the pedal gets firm only after half travel. My guess is that to get adequate pressure to the back I need to do it the old fashioned way, with a helper. Do I try more pressure with the toy, or get my wife out to the garage?

if you got BMWs up front, throw the prop valve away... far away... get a "T"... 'nuff said.

the prop valve will only cause you grief.

If you get a "long" but firm pedal, you do not have enough fluid capacity in the new system. I would guess that you still have the 17mm master cylinder and you need the 19mm one to supply adequate fluid capacity due to the larger front caliper pistons.

Like most things, this "UPGRADE" isn't. All you have done is "upgraded" the amount of heat the non vented rotor has to dissipate. You have also increased the front piston diameter vs the rear upsetting the brake balance, biasing it further to the front. This is why you can throw the proportioner away, the rears are no longer doing anything except probably increasing your stopping distance.