worf928

One trick I've used on the 4-piston Brembo calipers is to smack them (not hard) a few times with a rubber mallet when you open the bleeder. Sometimes you get bubbles that just won't come out unless persuaded.

IcemanG17

Some 928's have firm brake pedals....others have mushy brake pedals and everywhere inbetween...but assuming everything is working properly....they will stop really well when needed......

With that said....the high firm pedal still just feels better....

FlyingDog

After replacing the soft lines with the Goodrich lines from 928 Intl and bleeding twice, the pedal was much firmer. I didn't need to touch the ABS. It still has too much slop at the top but that might be in the linkage. They worked well enough to make the street pads mush in about 15 minutes on a 35* day.

Charley B

What do you mean?

SeanR

I agree, my '88 has very firm brakes and the '90 is much softer. I've bled both and not much of a change. I'm going to put some SS lines and see if that makes the '90 stiffen up.

Mrmerlin

make sure the pushrod is ajusted correctly from the pedal to the master cylinder/booster, it should have a bit of side to side play so to let the master cylinder return to its stop.

FlyingDog

I pushed the brake going into turn 5 and although the pedal was a little soft, there was no braking. The second push slowed me enough to make the turn. Gentle braking for the next lap brought back almost full braking. I checked after the session and I didn't boil the fluid so it had to just be the pads.

I don't know exactly what happens to cause this. Maybe gases generated by heat?

Charley B

I would certainly consider the fluid the most likely culprit. If you haven't replaced the fluid I would highly recommend it. As Stan suggested, ATE Super Blue or Gold.

Charley B

In reading your last statement again I'm not so sure it is fluid. If you mean you still had full pedal but no braking that doesn't sound like fluid. But if the pedal was going away then it does.

FlyingDog

The pedal was a little softer with almost no braking. Boiling the fluid should make the pedal soft until the fluid is changed. The braking mostly came back after going easy for a lap, and had completely come back by the next session. My instructor who is a professional instructor (that is his day job, lucky bastard) and weekend racer (#3 in his class this year) blamed the pads.

The fluid in there now is Valvoline Synthetic because I was tired of pumping $11 can after $11 can of ATE Super Blue through it. Now that the problem appears to be solved, the next change will be either ATE blue or gold since I do still have a can of each.

BTW, my ABS doesn't work. I locked the Hoosiers several times and the light was on most of the day.

IcemanG17

Some great advice I got about braking during track events is "brakes are like an on-off switch, its either all or nothing" this limits the time the brakes are applied, hence keeping them cooler...the worst you can do is be afraid of the brakes and drag the brakes for longer to accomplish the same braking as a short hard effort stop.....this really heats up the brakes..

Of course the track design has alot to do with it too....

FlyingDog

Brian, that is very true. My roommate (Beer Burner with his NA944) and I both heated our brakes up early with over braking. By the end of the day I was only braking for 5 of the 10 turns (and all the slow 325/M3s, Vettes, Audis, RX7s, and WRX/STIs).

Picture from my instructor "Matt with his rocket ship" "Oh and yes...the 928 was freaking fast ! Damn."