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

[Rodney Moore <m6bigdog@xxxxxxxx>]

John,
>>>>>>>>
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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!
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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.
>>>>>>>

To locate and solve an oil leak problem, Clean the area with Gunk or Simple 
Green so it is clean as a whistle!!  Oil leaks in general can only be 
located when there is no residual oil and grime in the area!!!
In the area of the Brake Pressure Accumulator/Regulator assembly make sure 
to clean the switch contact covers on the pressure switches.
Once the possible leak areas are clean start an inspection process;
Start engine and make an observation to see if the source of the leak can 
be located.  If not!
Take the car out for a short drive, then make an observation to see if the 
source of the leak can be located. If not!
Make daily observation to see if the source of the leak can be located.

I have also used paper towels by tying and/or stuffing them around a 
suspect sensor or fitting to help isolate the leak.  This can also help 
keep the oil leak from re-oiling your clean engine compartment.
On the Brake Pressure Accumulator/Regulator assembly there are two pressure 
switches (that are as problematic to leaking as engine oil pressure switch 
since  they perform the same type function) and there are connecting hoses 
and an "O" ring  that seals the Pressure Accumulator(brake bomb) to the 
regulator.
Since you get a brake warning indication, it is possible that one of the 
two pressure switches has a failed diaphragm which is what usually makes 
these switches leak!!

Happy Hunting,
Rod...


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Rodney Moore
e-mail: m6bigdog@domain.elided

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