From: N8N on
On Sep 18, 4:00 pm, dsi1 <d...(a)humuhumunukunukuapuapa.org> wrote:
> Scott Dorsey wrote:
> > dsi1  <d...(a)spamnet.com> wrote:
> >> Scott Dorsey wrote:
> >>> Jeff Strickland <crwlrj...(a)yahoo.com> wrote:
> >>>> I drove (rode)  my BMW dead-stick down a mountain road for about 7 miles.
> >>>> Steering was no problem, brake effort was high, but not a problem.
> >>> Shoulda got an E28.  You get several minutes of braking with the engine
> >>> off, courtesy of the nitrogen ball.
> >> What is a "nitrogen ball?"
>
> > It's a compressed gas reservoir that keeps the braking system up to pressure
> > after engine power is lost.
>
> > The brake system on BMWs of that era is... really German.  They never use one
> > part when they can use five instead.
> > --scott
>
> That's a good idea. I used to have a VW Rabbit that had a vacuum
> reservoir that looked like bunch of plastic spheres. I think it was
> hooked up to the emission system - not the brakes. How does this
> nitrogen ball work? The brake booster systems I'm familiar use the
> engine vacuum to multiply brake pedal force.
>
> As far as German engineering goes, I was very impressed with the rear
> drum brake system on a Scirocco I used to have. They replaced the
> standard self-adjusting drum brake wear hardware - starwheel, ratchet,
> linkages and springs, with a simple wedge and spring. It's a beautiful
> system. Mostly, I'm afraid of old-school English engineering. :-)- Hide quoted text -
>
> - Show quoted text -

The E28 BMW used a hydraulic booster somewhat akin to GM's Hydroboost
not a vacuum booster so the nitrogen ball was to keep the hydraulic
system pressurized when the pump couldn't keep up, so you didn't
suddenly lose brake pressure or steering assist. i'm assuming that
that was for packaging reasons because IIRC the 528s used a
conventional vacuum booster but the 535s (different, larger engine
block) used the hydraulic. I actually had a 535 back in the day and
just before I sold it I believe the "bomb" failed - symptoms were that
you would step on the brakes and there'd be a delay of about a second
or so before the boost kicked in. A little disconcerting, but I ended
up selling the car (cheap) because I was moving so I never had it
fixed..

Nate
From: N8N on
On Sep 23, 11:34 pm, ACAR <gmw...(a)gmail.com> wrote:
> On Sep 17, 2:41 am, john <johngd...(a)hotmail.com> wrote:
>
> reminds me of the runaway Audi stories...
>
> in the Audi case the gas/brake pedals were too close together and not
> aligned with the seat like other cars so drivers were simply stomping
> on the gas when they thought they were on the brake. (Manual shift
> Audi drivers loved the pedal placement, of course.)
>
> in this case the fault is said to lie with improper floor matts; not
> with a driver too dumb to recognize the problem and place his foot
> under the gas pedal and pull it up to free it from the matt. I had
> this happen to me years ago in some borrowed car.
>
> My Toyota car has a nice hook to hold it's driver's side floor matt in
> place. That's more than I can say for my Honda or GM products.

My '08 Impala has a hook on the driver side floor for the floor mat,
but the ones that came with the car are stored away in a safe place
while I'm using molded WeatherTech mats (which are great, by the way,
even though their advertising seems a little cheezy. I still prefer
the heavy black rubber ones that VW offers as an accessory through
their dealerships, but GM apparently doesn't see fit to offer a
similar product.) The thought of putting tan-colored carpeted floor
mats in a car that is used for visiting construction sites seems a
little silly to me.

I'm trying to remember if the '05 had a hook and now I just don't
recall.

nate
From: Mike Hunter on
If one had followed the Audi case they would have discovered the NHTSA ruled
the cause was DRIVER error, period.


"ACAR" <gmwohl(a)gmail.com> wrote in message
news:af985374-a9e4-46a3-b991-eed3d2d19c73(a)j9g2000vbp.googlegroups.com...
On Sep 17, 2:41 am, john <johngd...(a)hotmail.com> wrote:

reminds me of the runaway Audi stories...

in the Audi case the gas/brake pedals were too close together and not
aligned with the seat like other cars so drivers were simply stomping
on the gas when they thought they were on the brake. (Manual shift
Audi drivers loved the pedal placement, of course.)

in this case the fault is said to lie with improper floor matts; not
with a driver too dumb to recognize the problem and place his foot
under the gas pedal and pull it up to free it from the matt. I had
this happen to me years ago in some borrowed car.

My Toyota car has a nice hook to hold it's driver's side floor matt in
place. That's more than I can say for my Honda or GM products.


From: dsi1 on
N8N wrote:
>
> The E28 BMW used a hydraulic booster somewhat akin to GM's Hydroboost
> not a vacuum booster so the nitrogen ball was to keep the hydraulic
> system pressurized when the pump couldn't keep up, so you didn't
> suddenly lose brake pressure or steering assist. i'm assuming that
> that was for packaging reasons because IIRC the 528s used a
> conventional vacuum booster but the 535s (different, larger engine
> block) used the hydraulic. I actually had a 535 back in the day and
> just before I sold it I believe the "bomb" failed - symptoms were that
> you would step on the brakes and there'd be a delay of about a second
> or so before the boost kicked in. A little disconcerting, but I ended
> up selling the car (cheap) because I was moving so I never had it
> fixed..
>
> Nate

Thanks for the info. I have never heard of the Hydroboost system before
but a web search took care of that right quick. :-)

It seems like a nifty, compact system and from what I've read, provides
more linear braking. From the retrofit instructions, it seems pretty
easy to install, although there doesn't seem to be provisions for ABS.
OTOH, these seem to be mostly retrofitted to trucks.
From: aemeijers on
N8N wrote:
> On Sep 23, 11:34 pm, ACAR <gmw...(a)gmail.com> wrote:
>> On Sep 17, 2:41 am, john <johngd...(a)hotmail.com> wrote:
>>
>> reminds me of the runaway Audi stories...
>>
>> in the Audi case the gas/brake pedals were too close together and not
>> aligned with the seat like other cars so drivers were simply stomping
>> on the gas when they thought they were on the brake. (Manual shift
>> Audi drivers loved the pedal placement, of course.)
>>
>> in this case the fault is said to lie with improper floor matts; not
>> with a driver too dumb to recognize the problem and place his foot
>> under the gas pedal and pull it up to free it from the matt. I had
>> this happen to me years ago in some borrowed car.
>>
>> My Toyota car has a nice hook to hold it's driver's side floor matt in
>> place. That's more than I can say for my Honda or GM products.
>
> My '08 Impala has a hook on the driver side floor for the floor mat,
> but the ones that came with the car are stored away in a safe place
> while I'm using molded WeatherTech mats (which are great, by the way,
> even though their advertising seems a little cheezy. I still prefer
> the heavy black rubber ones that VW offers as an accessory through
> their dealerships, but GM apparently doesn't see fit to offer a
> similar product.) The thought of putting tan-colored carpeted floor
> mats in a car that is used for visiting construction sites seems a
> little silly to me.
>
> I'm trying to remember if the '05 had a hook and now I just don't
> recall.
>
> nate

My 92 Taurus did, and it worked. I miss it in the other cars I have had
since then.

--
aem sends...