Re: Bomb Warning removal <- Darwin was right.

[Robert Houk - SMCC Bos Desktop Hardware <rdh@UrQ.East.Sun.COM>]

   After driving Eric's car this past weekend, I feel that I must comment 
   on this thread.  The brake feel on his car was excellent, with no 
   superhuman force needed to stop, or slow, the car quickly.  Having said 
   that I guess it is still a matter of preference, but I prefer the less 
   boosted feel of Eric's car

Removal of the bomb does not affect the *amount* of brake assist, only the
way it "comes on". While the hydraulic system is under a lot of pressure,
the pump can only supply a small amount of delta per instant of time. The
bomb on the other hand, stores a LOT (relatively speaking) of pressurized
fluid, and thus can respond to instantaneous demands of the braking system
while the engine/pump gradually (1/10 second) replenishes the bomb.

Without the bomb, if you want FULL braking instantaneously ("panic stop"),
then you must provide the full brake-actuation pressure with your foot on
the pedal. Gradually (1/10 second or so), the pump fully pressurizes the
"new demand" and you need MUCH LESS pressure for the same brake-actuation.

The typical result is, in order:

 o   Situation arises requiring IMMEDIATE/MASSIVE/"panic" slowdown

 o   You romp on the brake pedal with far more force than you ever normally
     use in day-to-day driving

 o   Nothing happens, except the pedal seems like it is not moving at all

 o   The engine/pump is starting to build up pressure/assist

 o   You ***STOMP*** on the pedal for all you're worth

 o   The engine/pump succeeds in building up full pressure/assist

 o   All four wheels lock up simultaneously

This whole scenario is 1/10 to 1/4 second . . .
   
   ah, but Eric--you've done prob'ly had a few more btdt than the typical list
   member here ;)

   more seriously--if the accessory drive belt breaks, a bad bomb means no more
   (or very little) brake boost--i sure hope the typical list member likes
   *major* one-leg presses if that belt breaks when you need brakes (sorry,
   couldn't resist)

No, actually. Loss of the pump drive leaves you with a fully-charged bomb
good for 20-40 full brake-actuation cycles before it is fully discharged.
You will lose the power-steering immediately, however.

The first time my belt broke (well, I assume it broke, 'cuz it wasn't there
no more!), I was only one exit and a few blocks from the dealer (from whom
I had just gotten the car back the day before...hmmm...). Knowing that the
"power brakes" and the "power steering" were one integrated system, and
having full braking assist, I assumed I had a catastrophic failure of the
steering system . . .

I was able to negotiate the exit, several sets of lights (all against me,
natch!), etc., and so forth, and arrive at the dealer with tired arms 
(those damn cars are HEAVY; steering is HEAVY with no assist) and full
"power brakes" still in effect.

In its own way, it's a neat system -- loss of power-steering is a heads-up
warning that you will soon lose you power-brakes, and you should start
thinking about that while it's not yet a real issue . . .

I should preface the above (but I guess I'm postfacing it instead) by
noting this is wrt '83 UrQ (about which nothing is simple and straight-
forward, with the possible exception of replacing the radiator-mounted
fan switch); Y*MV.

					-RDH