Snow Cover On Roof Provides Wind Protection?

[Doug Miller]

Not true. The parking brake uses exactly the same pads that the service brake uses, except (as noted) on only two wheels instead of all four.

[Harry K]

No, the deaths and accidents are the fault of stupid drivers. Anyone who doesn't know enough to at least put it in nuetral or turn off the ignition does not belong behind the wheel. Too bad that that encompasses at least half of the drivers out there.

Harry K

[Harry K]

I _know_ it was the driver's fault. There is no debate about that. He was just plain stupid.

Harry K

[salty]

Good grief!

[Harry K]

AS far as Toyota goes, at least _some_ of it is an electronic problem. A 'stuck throttle' does not cause acceleration unless the driver is already accelerating when it sticks.

I saw a clip yesterday on the news where a woman crawled into a parked car, started it. jumped curb, across sidewalk and 1/2 way into a store. Stuck throttle was her excuse. It must have also caused the car to shift into drive instead of reverse. Riiiigggghhhhttt.

Harry K

[Tony]

Vacuum assisted brakes have that large vacuum canister with a check valve. A second or so idling and it has enough vacuum to work, and a check valve so it works if your throttle is to the floor, or your engine dies, it still has enough vacuum for a couple pumps. Try it with your car in the driveway. Put it in park, turn off the engine, then pump the brakes. You should get 1 to 3 good pumps before you feel in the pedal that the vacuum assist is not working anymore.

[Tony]

HOO BOY! And a Woo Hoo!

20% braking at the very most. At highway speeds after accelerating uncontrollably they will get too hot to work long before you can stop the vehicle. And no way will they make a difference if the vehicle is still in gear. Didn't we go through this recently? They don't even call them "emergency brakes" any more. They call them "parking brakes".

[Tony]

When using the rear brakes with the brake pedal, they give about 20% of the braking power. That is with vacuum assist! Using the parking brake lever or pedal they provide even less braking power with no vacuum assist.

[Tony]

Dang, you can't even do "line lock" burnouts!

[Doug Miller]

I didn't say they provided equivalent braking power. I just pointed out that they use the same pads as the service brakes.

[Jim Yanik]

[e-mail] (Doug Miller) wrote in news:hmj8jt$b13$ [e-mail]:

Or just at a considerable speed.

yes,the LEAST effective pair of braking wheels. He IS right about rear brake pads being smaller than the fronts. Most of a car's braking is from the front pair of wheels. Also,disc brakes don't perform well without hydraulic power.

This has been my experience.

[Jim Yanik]

[e-mail] (Doug Miller) wrote in news:hmj8gb$b13$ [e-mail]:

Yes,exactly. If one's foot is on the brake,the throttle should naturally go back to idle. although,it would cause some trouble for left-foot brakers when they unknowingly ride the brakes. Hmm,might teach them to properly brake,with the right foot. B-)

[trader4]

Do you know for sure how the shift mechanism works on all these cars? The throttle is fly by wire, what makes you so sure there isn't something similar for the tranny that could block it from being moved into certain positions under certain conditions? That even seems desirable, does it not? Like preventing it from being moved into park while it's moving?

As for the 3 seconds to shut the engine off via the starting button on the Lexus, that is indeed the case. And it's worse than that it could take 3 seconds while roaring down the highway. Who would know that it takes 3 seconds and hold the button in for that long? Apparently it takes 3 secs while the car is moving, which is not the normal shut-down sequence you would experience everyday. In fact, you'd most likely only experience it when something was seriously wrong. And then it would seem more likely many people would continue to push the button again and again instead of just holding it in. To top it off, the Lexus was a rental, so the driver had no familiarity with it.

I'm quite amazed at how people want to just attribute this to driver stupidity. In the famous Lexus case the driver was an experienced CA highway patrol officer who had taken special driving training as part of his job. I'd be pretty amazed if he didn't try to put the car in neutral.

[trader4]

Maybe on YOUR car, but not on my Mercedes. The parking brake pads are completely seperate. I'm not sure what various other manufacturers do. I'm sure others as you say do use the same pads. But even if they do, it then has even less relevance to stopping the car under runaway conditions. If you're already standing on the hydraulic brakes that use the same pads, applying the parking brake isn't going to do anything,

[trader4]

Very good question and apparently one of the key differences between Toyota and the other manufacturers that do have it. Another question is if the design other manufacturers used involves the computer doing it or if there is some seperate circuit that does it. The obvious problem being that if the computer is the interlock mechanism, then when it's going nuts and ordering full power, it may also be incapable of executing the safety program as well.

[Hell Toupee]

More the fault of the car dealership that gave him that loaner car even after the previous customer who'd used it reported the sudden acceleration problem to them. They loaned it out again anyway.

[Jim Yanik]

Hell Toupee wrote in news:hmjgjd$equ$ [e-mail]:

It's common to have failures that are not readily repeatable by service techs. You can't fix when you cannot diagnose,because the reported problem did not occur when checking it out.

and isn't the operator responsible for learning about the engine shut-off procedure from the Operators Manual? Even if it's a loaner?

[salty]

The operator should have known there was a problem, diagnosed it and fixed it properly before leaving the dealership. He must have been stupid.

[dpb]

Other than possibly being in very close quarters at initiation of the event, one has to wonder what actually did happen other than panic and inappropriate or incorrect response. If one were in a parking space and it surged, it would be highly likely to hit something directly in front/rear before had time to react. Similarly in close traffic. But on open road as many seem to have been, one wonders why the disasters, indeed.

But since there are no black boxes and personal recounts are notoriously inaccurate (both for lack of actual recollection and knowledge as well as for face-saving reasons) there's really no way to know what any individual did in any given circumstance. And, of course, if there's not a record of failure to respond to an input as well as the response, even a black box wouldn't be the unequivocal answer, either.

And, unfortunately, there's no equivalent of air-crash safety post event forensic investigation so afaik there's been no exhaustive study of any of the events beyond simply police/highway patrol routine accident reports. What, if anything, Toyota has done from any of the reports is not publicly available altho one presumes at least something.

The CA incident is indeed the most mind-boggling of all I've heard and doesn't say much for CHIPS training if actually was anything other than a desk-bound supervisor or somesuch individual behind the wheel.

Panic and untrained/unskilled drivers certainly have a large component to play in end results methinks as well even though the initiating event is hardware/software related it appears...

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[trader4]

Going slow enough? According to your own source, which I think is an excellent one, even at 120MPH the brakes were capable of slowing the car to 10mph. At that point, if all else failed you could stear the car off the road into a guardrail, ditch, or some similar roadside place to bring it to an end.

How were the brakes compromised?

[still- it looks like

How do you know that they didn't try that? With a CA highlway patrol officer that was trained in police driving techniques and surely isn't an idiot driving, I would strongly suspect that they would have tried it.

It would work if the circuit that cuts off the throttle when breaking is independent of the computer.