braking in reverse

[Bobsprius]

Sure hope 48/50 doesn't want to return the car for this. I don't think that is reasonable at all. Again I would hope all the benefits outweigh this small as I believe non issue. Doesn't matter what vehicle for that matter all have some glitches and bugs and this is no different...

[rachaelseven]

Originally Posted by Bobsprius

Knock on "wood" it has not happened to me once yet. I have a sloped driveway, nothing yet. OK so it's only been about 3.5 weeks, but some posts have seen this early on.

I have not seen any Technical Bulletins and the Dealer I was just at to pick up my Cargo Mat, I spoke to the Service Dept about it and he said they have had no known complaints. He did look in the computer..so I am sure he looked at some records...

I am starting to wonder if this has anything to do with the way people leave there vehicle, meaning, everyone who has experienced this are they pushing the PARK button when parking before turning off, or letting it go to PARK in the Auto format, by pushing the power button? Are they waiting a 15 seconds before backing up, giving the systems time...there's something that's a fluke with this, since if it was across the board to all drivers, I would think it would be a defect and recall process. Have we looked at a specific model to tell if it's related or option group?

I agree it's getting old and we need a good definitive answer...

Finally! If not answers, at least we have someone with some reasonable questions instead of another poster telling me I don't know how to use the brake pedal. Thank you! To answer some of the questions:

1. IV w/Solar & NAV
2. I do sometimes park by just turning the car off and letting it move to park as part of the shutdown process. I do that a lot though, and cannot correlate it specifically to the one time this problem occurred.
3. I do not always wait 15 seconds either before or after putting the car in gear. In fact, I very rarely do. So again, I cannot correlate that action to the problem.

All very good questions, even though I don't have any useful answers. Lets continue to explore these types of helpful lines of reasoning - it doesn't seem to happen to all owners, but it is certainly not an isolated case.

[Pugsy]

For me:
1. IV w/solar and NAV
2. I always push Park before turning off the car, no exceptions
3. I do usually wait at least a few seconds, though not 15. Today when the grabbing happened I was in quite a hurry, so probably didn't wait at all.

[Bobsprius]

Raechelseven,

I agree, there has to be some sort of commonality to the issue. Again there is some steps or processes that may be different. Some of those you listed like not waiting 15 seconds (that was just a mean number I picked as I would think all component go through a quick check process), and using the Park Button each time when stopping at your destination versus using the POWER button only.

I know nobody has provided any solid evidence to date of what this issue is, and speculation is quite the norm. I may suggest to that you should try those 2 steps mentioned, (faithfully) for a period of time, I know it may be difficult since it's procedural and your not used to performing it daily, but if you do this I wonder if you won't exhibit the behavior? Since I have not noticed it yet, I follow that regimen daily and on all trips so maybe it has something to do with pressures, computer routines, something for sure...of course there is a possible software upgrade or something, but try those steps to see if you DON'T experience it. I have a Model V and from looking back in the posts I do see it across IV's and a V and also III. So the Model theory may be dead, but I also have no precluded it to be a specific option group either. More to come, but thought this may be a good place to try and "Self Evaluate".

Thanks again!
Bob

[Bobsprius]

RechealSeven,

Based upon PUGSY's comment:
"Today when the grabbing happened I was in quite a hurry, so probably didn't wait at all. "

I just think it interesting...nothing against you Pugsy just trying to get more info to make some rationalization to the issue...But that was helpful and honesty is good!

[Pugsy]

The more info the better, I say. I'll have to note how long I waited if it happens to me again.

[rachaelseven]

The hurry theory certainly has some intuitive appeal... reasonable theory. The problem is, I pretty much always do the same rushed exit and it's only done it the one time. It's not that I'm actually in a hurry, but there just doesn't seem to be any point in waiting, so I just go. So in my case, the absence of the behavior wouldn't prove anything... would only disprove the theory if it did happen again. Some other posters seem to be having the issue more frequently though, so perhaps someone who has it weekly or more could try out the suggestion and see. At least we're working on the problem with some good old fashioned collaboration - thank you Bobsprius!

[jburns]

Originally Posted by rachaelseven

The hurry theory certainly has some intuitive appeal... reasonable theory. The problem is, I pretty much always do the same rushed exit and it's only done it the one time. It's not that I'm actually in a hurry, but there just doesn't seem to be any point in waiting, so I just go. So in my case, the absence of the behavior wouldn't prove anything... would only disprove the theory if it did happen again. Some other posters seem to be having the issue more frequently though, so perhaps someone who has it weekly or more could try out the suggestion and see. At least we're working on the problem with some good old fashioned collaboration - thank you Bobsprius!

I've onky experienced grabbing brakes once in 2500 miles. I almost always put it in gear and go as soon as the "ready" symbol appears. After all, isn't that what ready means?

[spiderman]

I have only had this happen once. We stopped at a store, the wife went in to shop and I left the car "on". We sat about 12-15 min. Backed out of our spot (level parking lot) and it happened. We previously traveled about 30+ miles before getting to the store (the car was warm and certainly no RUST on the rotors ).

At this point I am not worried about it but it sure would be nice if it was diagnosed.

[brad_rules_man]

Without reading all 11 pages, I'd have to say it happens on most cars, but is more noticeable on the Prius. For one, it's extremely light, and now has 4 wheel disc brakes. The regular brake wear-in is in the forward direction, and when you go in reverse and tap the brakes, it is creating friction with the pads contracting on the rotor which is going in a reverse direction. Being a lighter car, it doesn't have the same momentum to overcome and overwhelm the slight braking. That's just my theory.