Icy drive, ABS kicks in, truck keeps moving


#1

This is my first vehicle with ABS and automatic transmission and I’m wondering if the following behavior is normal, or if I need to have the brakes looked at.



First, I have a very icy driveway.



I have a 2005 Tundra. In the morning when the idle is high (1200 rpm), this beast really wants to leap forward. So I’ll put my foot on the brake to slow it down (I’m only moving at 1-2 mph). But because the driveway is icy, the wheels lock, the ABS kicks in and the truck will actually continue to creep forward (very slowly) despite having my foot hard on the brake.



Is this normal? With previous (non ABS) vehicles, the vehicle would eventually slow and stop in this situation.


#2

Yes, it’s normal.

The engine is running at high idle and pushing the truck forward. If you shifted to neutral the truck might stop, but on ice, and depending on the steepness of the descent, it’s not guaranteed. Try creeping down the driveway in neutral and see if it helps.

It shouldn’t be this bad once the engine warms up and the idle falls to normal speed.


#3

I don’t know about the Tundra, but it’s not normal for my cars with ABS. Yes, on ice it takes a while to stop and the ABS activates. Once stopped, the ABS shuts off and the wheels stay locked.


#4

Yes it is normal. Under the conditions you describe and pointed out by mcparadise it is totally normal. BTW without ABS you might have slid down the drive, but you would not have had any control over direction.

ABS is designed to give you back some direction control.  It does this by giving up a little stopping power, but in most cases it is far safer to loose a little stopping power, and maintain direction control.

#5

Yes, this is normal. Until you come to a ful stop the ABS will continue to interfere and your truck will keep moving. On a descent that can be impossible. I have a hill by my house that I don’t even bother to go down when the roads are bad because the car will just keep going.

ABS has some serious limitations. You’ve discovered one. The other will be on gravel roads, so be careful there too.

Stinks, huh?


#6

Forgive me, but I have to ask.

Are you sliding on the ice on winter tires or so-called “all season” tires?


#7

They are “all season” and I’ve been considering winter tires because of this situation. The truck also has four wheel drive (again, a first for me) so I thought I’d see if I really needed the extra traction. And with the exception of ice (always the exception), the truck does pretty well with the all seasons.

From what I’m seeing here, it would seem that the behavior is normal, which at least means I don’t have to get the brakes fixed… maybe just snow tires.

Now of course, I feel compelled to mention that in my 35+ years of driving cars and trucks with no ABS, I have never had a problem – I just pumped the brakes like I was taught. But I also know doing that will start an entirely new debate, which (I’m holding my hands over my ears) I don’t want to subject everyone to.

Thanks for the input! Very much appreciated.


#8

Yep – see my comment below!


#9

Egad, ABS does not increase the coefficient of friction?


#10

The winter tires are worth a try.

I’d been driving without problem for over 37 years when I got my first ABS equipped car in '05. I quickly discovered the weakness on icy roads.

Don’t fear, we’ve had the debate numerous times before. There are definitely two points of view, one from those of us above the snowline and another from those of us in the sunshine states. Personally I think ABS should be able to be switched on or off by the driver, or perhaps be an option on all cars.

The auto editors all seem to have bought into the farce. They all write that ABS should be a factor in one’s car-buying decision.


#11

The “snow tires” from years ago are not technically the same thing as modern winter tires. Winter tires have come a long way in terms of performance. Your ABS and other safety features will work more effectively when the tires have more traction.

The more I think about this, the more I believe winter tires will help. Because the ABS detects a lack of traction, it is keeping the brakes from stopping the truck. Add more traction and, hopefully, the problem will go away.

Be sure you let us know how it turns out.


#12

Will do. I’ve started researching tire and wheels… probably creating a whole new topic. I had reasonably good traction and stopping power with my '98 2wd Ford Ranger which had studded snows and sand in the back.


#13

How do we get this point across? is it hopeless?

All bets are off on ice,get the ice off the road is the only thing that helps (maybe those tires with the big spikes will make me a liar)


#14

rarely do comments on this board make me literally LOL, but that one was good.


#15

In spite of all the theorizing about ABS and tires, if your engine is racing while still cold, and it’s an automatic in drive gear, it’s literally trying to push you down the driveway against your efforts to stop. I always found it better to ease down the driveway with the engine running, but in neutral. I can’t tell you how many times I slid off the driveway into the grass before I figured that out.


#16

Yeah its normal. Put the thing in neutral until you get to the end of the drive. Just like 4 wheel drive, ABS does not increase traction but only helps you get the most traction possible. When the most traction possible from the tires is exceeded, you will slide down the driveway anyway.


#17

ABS function is retain steering control under hard or severe braking conditions. If your tire locks you cannot steer.