Brake light flashing 5kcs

[Iain Mannix]

Hi all - gt my new 86 5kcsq; overal in good shape, a bunch
of little fixes here and there(IE, dash lights intermittent,
snagged the relay out of the wagon, fixed), but it has developed
a brake warning light flash.

No leaks.
Pedal/steering feels fine.
Belt seems tight enough.

??? Bomb?

Here's the weird one - when it first started happening, I
looked at the level - 1/2 way between the Min and Max lines.
OK, will fill it.

There was NOTHING in the reservoir(beyond fluid).  My 87 has a
washer with a hole, spring and plunger for the level sender.
Weird thing is, the light did not flash ONCE before that, and
I'd not taken the cap off (1/2 way between min/max, was going
to fill it, but that'd not gotten my attention).

Anyway, no plunger/float, no spring, no washer.  Grabbed that
out of the 87, went for a drive.  "OK" on the multifunction
dealie.  10 minutes in, brake light.  HMMM.

Stopped and looked - the cap on the pentosin reservoir had
cracked up the side of the threads.  OK, that makes sense -
I'd not thought the reservoir would've leaked, but whatever.
Put the cap from the 87 on, refilled, OK again.  Then a
light.  HMMMM. No fluid loss, nothing "wrong," but a light
nonetheless.

I wonder if someone put something in the cap to stop the
low level warning & ran it without the plunger.  Just got
the car, previous owner unknown(although the car does not
look like it was owned by a hack).

So, it has a non-cracked cap, spring/plunger, full reservoir,
plug on cap is firmly seated, etc - what could it be?  I don't
KNOW that something was wedged in the cap/sender unit & fell
out, but I did drive it 50+ miles before I discovered the
absence of plunger.  I can't think of any way it would not
have complained without the plunger.  The guy I bought it from
recently started driving it again(abandoned at a shop), he'd not
seen any brake warning lights.

Now, the light is intermittent - any thoughts?  The bomb seems
OK, no leaks, full level.  ABS light is intermittently on and
off - can they be related(dirty pickups by CV joints, I
think).

Kinda a weird one.  I like the car, full throttle switch
fixed the boost, starts well, drives nicely, etc etc etc -
but it is seeming that I cannot own an Audi without some
weird, inexplicable problem.

Or should that be "we?"  Thanks!



Iain