E-30 spongy pedal

[JHahn22@xxxxxxx]

Hello again folks,
I've had this problem for a while and it's driving me nuts.  The car is an 87 
325i with about 200k on it.  When I first got the car, I noticed that the 
pedal felt pretty spongy, although it still brakes pretty well in general.  
There is just no hard "bottom" to the pedal till it hits the floor.  You 
really have to apply very hard continuous pressure to the pedal to make it 
sink that far though.  Although for really really hard high speed braking 
(like in twisties in oak creek canyon on the road to Sedona from the Grand 
Canyon :-)))))) it did get really scary a couple of times.
In trying to fix the problem, I flushed the system, changed the Master 
cylinder, flushed and flushed with a pressure bleeder.  I've searched the 
whole brake sys several times for leaks, peeling up the caliper piston boots 
and everything and I can't find anything that looks wrong.  When bleeding the 
rear calipers I've bled for ever and continue to get an intermittent stream 
of bubbles, but can't figure out where they're coming from.  The fronts 
flushed out without much trouble.
I'm starting to wonder if the brake fluid in the ABS system needs to be 
flushed somehow, or if there is some other ABS related issue.  Compared to 
the 89 e30 I used to have, the pulsing in the pedal feels pretty week when it 
engages.
Any thoughts would be appreciated.
Thanks in advance,
Jake Hahn
87 325i
Austin TX

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