Is it the "bomb" or master cylinder? 5000

["Gregory Dillon" <gdillon@jps.net>]

Over the last three weeks I've had symptoms of brake problems.  I believe I
need to change either the Master Cylinder or the "bomb" (what a name).  But
which?

Here is what has happened.

The Check Diagnositics graphics showed the picture of the "bomb."  I added
petrosin fluid, it was at the min mark and problem seemed to be corrected.

Twice in as many weeks when stuck in traffic jam type traffic for over 40
minutes, -stop, shift, start, stop, swear . . .- my brakes have gone from
stopping at the top of pedal travel to more that half way to the bottom.

Second time, again in long traffic jam same thing.  Brakes only stopping
near bottom of pedal.   I turned off the car checked fluids and
temperatures.  Again the brakes fixed themselves somewhat and improved more
as I drove home.  Back to normal the next morning.

Yesterday, the "bomb" graphic showed for a second, and then turned itself
off during the auto diagnostic startup functions.

Should I change the bomb or the master cylinder?

Greg Dillon