Handling during a sudden stop

<div class='quotetop'>QUOTE(PriusRos @ Jun 26 2006, 05:32 PM) [snapback]276997[/snapback]</div>

 

I am not sure if this is your case. When my front right tire was low on pressure, the car turns right when I brake. After I make both front tire the same pressure, it never happen again.

 

I have a 2005 Prius with VSC and also had to stop quickly on the freeway. The rear of the vehicle suddenly swerved almost in to the other lane. It appeared as if the brakes locked. Conditions were dry and temperature was warm. I assumed that ABS should have prevented this but I guess not. No real answers to the handling issue.

 

<div class='quotetop'>QUOTE(mkaliski @ Jun 26 2006, 02:52 PM) [snapback]277003[/snapback]</div>

What was others' experience??? Mkaliski, what was the tire pressure at the time? This is kind of bothersome taking in account that the car has VSC and ABS....

 

No problems here. The various safety features did their job (2005 Prius w/ VSC). Most memorable experience was when the traffic came to a sudden stop on the downhill of a highway. No swerving as you describe, although I could "feel" the car making some adjustments I was not, but then again, that's what those stability features are designed to do.

I should add that some (perhaps most) drivers instinctively jerk the wheel when something suddenly happens in front of them, which consequently can cause a swerve and/or loss of control. Are you sure this is not the case in your situation?

 

If the tire pressure is normal, I would check the brake pads next. Even though, nowaday, pads are simply "floating" on rotors, sometimes, left/right sides simply grab the rotors differently. When braking hard, the vehicle may pull to one side.

In addition, Prius is a front-heavy (59/41% front/rear) vehicle (like most front drive) with tall stand (higher than most sedans/coupes). When braking hard, the rear end would be lifted due to weight shifting forward. The rear tires would lost traction a little. Therefore, it may be more likely to fish-tail. Just my assessment.

 

No problem here either. Just had to make a sudden stop the other day...everything went fine. I agree, a lot of driver's instinctivly jerk the wheel trying to avoid what is in front of them. It happens so fast that it is not a conscious reaction, so one would not remember doing it. Most of us are also used to pumping the brakes which is a hard habit to break with the new ABS systems.

However, sounds like you did not crash, so I guess things worked as planned as far as that.

 

I've had to stop a bit faster than I originally anticipated.
Throw the shift to B and brake I've found a big increase in braking effort and no problem stopping where I needed.

 

I experienced the exact same swerving after a sudden stop several times soon after I bought my car. I have a 2006 Prius, HK model #6 with ABS, traction control VSC, etc. I was going about 60 and slowing down to 30 mph on a dry road and the back of the car didn't follow the front of the car during the stops. I expected a straight controlled stop, but what I experienced was anything but. After having the car for 5 months, I haven't experienced anything like that recently. BTW, I have had Michelins on my car since day one, so this is not a tire problem nor is it a tire inflation issue.




<div class='quotetop'>QUOTE(PriusRos @ Jun 26 2006, 05:32 PM) [snapback]276997[/snapback]</div>

 

I had to brake and swerve to avoid an idiot Mini driver that got on the freeway slightly ahead of me (we were about even when he started this) and proceeded to fly across all 4 lanes of moderate traffic without looking, signalling, or even getting up to speed. I would guess they were going about 50 MPH durring this lane jump.

The ABS kicked in, Trac for a minute as I hit a little gravel. No VSC chime. I was able to brake HARD, and control the car just fine. 2006 #6. I thought the Prius handled the emergency braking quite well, much better than the other cars I have owned. I was going about 65 MPH in cruise at the time.

 

<div class='quotetop'>QUOTE(mkaliski @ Jun 26 2006, 05:52 PM) [snapback]277003[/snapback]</div>

I wonder if there would be any codes Toyota could pull. The brakes shouldn't be able to lock, not with ABS.

 

<div class='quotetop'>QUOTE(ceric @ Jun 26 2006, 06:01 PM) [snapback]277098[/snapback]</div>

If it's a U.S. car -- no pads, no rotors. We have four drum brakes in the U.S.

 

<div class='quotetop'>QUOTE(jbarnhart @ Jun 30 2006, 01:28 PM) [snapback]279195[/snapback]</div>

Actually, 2006 have discs on the front, drums on the back.

 

<div class='quotetop'>QUOTE(priusmatic @ Jun 30 2006, 10:58 AM) [snapback]279210[/snapback]</div>

Not just 06, all the 04 thru 06 have disc front drum rear in the U.S. and Canada. I think the earlier G1 is the same.

If I had the problem described I would try to duplicate it, after checking tire pressure of course. I have taken mine to a straight road with no traffic and crammed the brakes on as hard as I could to check ABS operation. I would rather find a problem that way than during a panic stop. It also lets me know what to expect. I think the brakes should have a couple of thousand miles on them first though.

 

<div class='quotetop'>QUOTE(PriusRos @ Jun 30 2006, 11:36 AM) [snapback]279235[/snapback]</div>

I agree brakes need to be "broken in" for a while, of course sometimes you have no choice except to step on them hard, such as in your situation. I tend to forget how busy roads are in some areas, around here it's no problem. But I think it would be worth it even it you need to go out into the Maryland countryside early Sunday morning or something. Let us know what you find.

 

<div class='quotetop'>QUOTE(jbarnhart @ Jun 30 2006, 10:28 AM) [snapback]279195[/snapback]</div>

Even someone who knew nothing about the Prius could look through the openings in the front wheels and see that there are disc brakes there (and drums in the back).