Runaway Prius in California....

[cjolley]

I still think there is something seriously wrong with the idea that the breaks can't stop a Prius, no matter what the engine is doing.

Unless there is some system that could rev the engine and disable the breaks at the same time somehow.
Stability control maybe? But do older Prius' have that?

[Sasq]

Don't get me wrong here doc, i think something is damn well wrong.
But it seems like half the damn cars i see on the road here are Pirus, and we are not getting the same issues here, it may be environmental or soemthing, but there is more then just toyota's screw up to it.

even more so, seeing as its so popular right now, at this stage I am not putting it past people who want an new car to take advantage of the situation.

Really I don't know what caused the latest issue with lady crashing into wall, but until there are more forensics on this, its equal 50/50 on toyota/old girl didn't like car, cash in. regardless of what the media is reporting - cause you know, media never spins a story to suit themselves and ratings at all

*edit - I just want to see this on a case by case basis, me, I drive a mazda so no pride there, just irks me when media jumps on the closest cashcow without actually investigative reporting.

[Dr Mordrid]

Too many cases to lay it off to the usual suspects, especially those cases where the floor mat has been taken out or restrained in a rearward position (some are taking to tying it to the seat platform with plastic ties) and the pedal not involved. Then there is the California case from earlier in the week; the 911 tape indicates that someone in the car tried to reach down and pull the pedal back up but couldn't - it was totally frozen in place.

Then there are the cases where the car took off without the pedal being stuck. Those point to an electrical issue, and at least one auto tech professor has duplicated it by simulating a short circuit due to corrosion/deterioration at a connector. Even duplicates the cars 'black box' not throwing an error code, which has been noted previously.

[Sasq]

I am also sensing a certain level of "oh its a toyota - must be their fault"
at least on this latest one, there just isn't enough info yet on that accident.
Toyota - probably, still not ruling out slip off of a high heel etc...

[MultimediaMan]

Judging from the frequency (or at least the reporting of the incidents), it seems as if there is a physical wear/ electricial breakdown issue here. Most of the cars having the problem are older models with a higher mileage.

[Dr Mordrid]

Link....

Another Prius speeds out of control, N.Y. police say

PURCHASE — A woman smashed into a stone wall this morning because of a stuck accelerator on a Toyota Prius, Harrison police said.

The 56-year-old driver suffered non-life threatening injuries, acting Chief Anthony Marraccini said.

The woman was pulling out of the driveway at 3700 Purchase St. facing forward when the accelerator stuck, police said.

The car "shot" across the street smashing into a stone wall, Marraccini said.

The collision sent "some pretty big boulders" fairly far, Marraccini said.

Marraccini said the floor mat has been pretty much ruled out as a cause. The 2005 car appears to have had corrective action taken, Marraccini said. The floor mat was tied to the seat base with plastic ties.

The car has been taken to police headquarters for further analysis.

The driver was being evaluated at White Plains Hospital Center.

[Dr Mordrid]

Yup, but with stick you can just as easily wear out the clutch.

[Wulfman]

right, I forgot - automatic... not as much of a problem with manuals, unless you go downhill a long way without knowing about engine braking.

mfg
wulfman

[Dr Mordrid]

In stop & go driving you're often constantly riding the brake to match the traffics speed, especially if idle creep is still too fast. That friction causes heat to build up and it is radiated slowly because of the mass of the the metal parts, eventually causing an overeat condition. Pads burn, the discs get hotter than hell, caliper seals can soften, fluid can boil and/or leak via the seals, the flex hoses can cook etc. etc.

Literally brutal. for "standard" brakes and street racing brakes for, say - a Matrix, that work fine hot could run $2k or more per axel. The caliper would have 6 pistons vs 1 or 2, be forged alloy vs cast iron and the rotors huge and highly ventilated. Pads cost a lot vs $30 for street pads. No normal carmaker will be making those standard anytime soon.

Standard brakes



High capacity brakes

[Sasq]

It happens from the constant accelerate/decelerate cycle on the highways, merging traffic, rubbernecking et al. its not as odd as it sounds

[Wulfman]

Brake fade from overheating is real, and can be serious. Had it happen to me. Got stuck in heavy traffic leaving Minneapolis once. Within about 15 minutes my brakes were smoking and I could tell they weren't doing anything anymore.

what exactly does heavy traffic do to the brakes to cause that much overheating? I know it is serious, and in the mountains there are a few tourists every year having problems (that's what run-out ramps are for ) - but heavy traffic? how?

mfg
wulfman

[KRSESQ]

Brake fade from overheating is real, and can be serious. Had it happen to me. Got stuck in heavy traffic leaving Minneapolis once. Within about 15 minutes my brakes were smoking and I could tell they weren't doing anything anymore. Had to pull off the next exit and coast to a stop and park for an hour to let them cool down. Checked it out when I got home and the brakelines had visible charring from the heat.

Kevin

[Dr Mordrid]

In the old days of no power steering the steering boxes gear ratio was far higher to reduce the effort, so even women could drive a pickup - my mom was quite good with dads old Ford F-1 (yes, F-1 - a 1952 flathead v-8). Some boxes had up to a 30:1 ratio, though something like a mid-60's Mustang might be 16:1.

No rack & pinion then; recirculating ball or worm/sector gears. You might have to spin the wheel a few times to get the lock power steering gives in <1 turn, and no variable ratios either.

Because of this common ratio difference vehicles with power steering are often far 'stiffer' to steer in PS failure mode than cars designed to be without it.

I've seen modern car brakes destroy their linings in a high speed overheat - the adhesive bonding the pad to its plate can let go or the friction pads binding agent can fail and it crumbles. I was in one that did it - a Maxima. Not to mention seals/hoses failing when the disc goes red hot, sometimes causing a fire. Seen that too, but not from the inside.

BTW: reports here say the affected Toyota's often have pads that are burned o a crumbling crisp, so those discs are very likely getting red hot.

That's why one of the first things a rodder or racer does is upgrade the braking system. Large, thick ventilated $$-alloy discs with ceramic or some other high-temp pad and very $$ alloy calipers.

[TransformX]

Hit the breaks, and I mean hit them hard, then turn off the ignition. Voila.

[Wulfman]

Breaks suffering a heavy load like that massively overheat and fade, making them useless (...)
Most of the experts that have weighed in on this problem advise against turning the vehicle off. Turn off a car with electric assisted steering, as most of the affected cars have - Toyota and GM who uses Toyota sourced electric steering parts in their compact cars, and you have greatly increased steering effort and little control, especially if you aren't that strong or female.

I can't believe that the brakes would fail from something like this. it takes a fairly demanding road downhill to kill a set of breaks (and for some reason that is something everyone here is actually taught ).

and the other point: for how long again have been females driving cars, even without assisted steering? as long as they just turn the key and keep it in, and avoid triggering the steering lock (now that would suck) you should be fine. after all, that stuff has been happening on the highway - if someone manages to survive driving there at uncontrollably high speed for 20 minutes, they should be able to switch of the engine and stop within less than 10 seconds, no?

mfg
wulfman