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Re: Da bomb

Thanks for all the responses. Gotta love that squeaky wheel thing (Oops,
that's another question, and no I don't have any squeaky wheels).

Here are some follow ups.

I get less than 2 pumps on the pedal. In fact I get 0. As soon as the engine
is turned off, the
brake pedal firms up. I know this is indicative of a bad bomb, but part of
my original (the original original one) question is "if the pump that
charges the bomb up goes bad than
I should get the same results, i.e.. 0 pumps to hard pedal. Correct? Bomb is
not being charged up?"

I am still not sure if it is a bad bomb. There is a constant pulsating
through the brake
pedal, even when there is no pressure applied. If I touch the pedal lightly,
with my hand, I can feel a continuous light pulse. When I brake hard the
pulse gets harder. All the while the brake light stays on (from start up to
engine off). The auto check system does not come on, but the brake light
that is also activated by the parking brake is the light I'm referring to.


-----Original Message-----
From: Al Powell <apowell@agcom.tamu.edu>
To: famoroso@sprintmail.com <famoroso@sprintmail.com>
Date: Thursday, April 09, 1998 1:34 PM
Subject: Da bomb

Frank, YES, you ahve it right.  When the bomb gets bad, it sdoesn't
hold pressure correctly.  There's a pressure switch screwed into the
brake MC which senses pressure in the hydraulic system.  When it
falls too low, that switch triggers and turns on your BRAKE light,
same as when the parking brake is on.

Remember, the hydraulics provide the brake assist, so this is not a
brake fluid warning, but a hydraulic system pressure warning.

This usually begins by flashing the light when you tap the brakes
more than once - causing the pressure to lower momentarily - and then
the light goes out as pressure builds again.  As the bomb weakens, it
takes fewer taps for the light.  You will also note that it takes a
while in the AM for the light to go off, as it takes longer to build
up pressure.

The bomb can be had for muat Audis at $250 or so.  Do NOT put a used
one on - these are perishable and it's a false economy.

The procedure for replacement is in the FAQ links on my Audi page,
which can be found from my home page below - look for Car Hobby

Al Powell                        Voice:  409/845-2807
107 Reed McDonald Bldg.          Fax:    409/862-1202
College Station, TX 77843