<E28> M5 Brake Light Telltale On!(Help)

[Im4BMW@xxxxxxx]

Fellow Bimmerheads,

I know I don't have an E36 ///M3, Z3, ///M Coupe or Roadster, or other "late
model" Bimmer, just a "lowly" E28 (they rule you know!)...but I received only
"one" response to my request for assistance on my brake telltale lighting
up/ATF loss in the Power Steering reservoir (prior to calling my mechanic).

Please set aside the beers Bubbas and try to help me on this one!!!!!!  

My car appears to have a leak somewhere in the power assist for my brake
system.  The brakes operate "perfectly"..no hard pedal, no travel to the
floor, etc.  just the dumb brake warning light coming on after the car has
been driven some...it usually comes on "without" depressing the brake pedal
even!

I crawled under the car last night to inspect where the ATF fluid is coming
from and found the underside of the floor pan soaked with something...ATF I
assume, BUT looking at all the hoses and fittings, including the underside of
the brake booster and the master brake cylinder, they looked dry as a bone!
The brake fluid is not leaking either.

The only place that looked wet at all was the brake "bomb" (all grimy on the
outside surface) and the pressure regulator (grimy too) where the low and high
pressure switches reside.

If the booster was leaking how could the bomb be all grimy(it resides above
the booster as you know)?  

Is it possible to have a leaking brake accumulator "bomb" that still functions
well enough that the pedal feels completely normal?

The brake fluid reservoir is "full", and if not for the ATF leak I'd think the
sending unit on the brake fluid reservoir had gone south.

I would really appreciate some input on this....if it's an easy fix like
replacing the brake bomb and a couple switches, I'm up to the task, but I
don't want to fool around with the big $ items like the regulator or the brake
cylinder(just yet anyway!)

Is anyone up to the challenge? 

Thanks to Curt Kiser for responding.  I checked the underside of the brake
cylinder where the "purge" fitting resides...it looked bone dry to me!

Any help very much appreciated.

John Weese
Landisville, PA
BMW CCA #76646
'73 2002tii
'88 M5

p.s. Sorry John Allen, I also posted this to the M-Formation Digest since I've
had so little response from the Big Digest. Regards.

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