ABS.. A System of Mystery

[brandon184]

I've noticed something... Whenever I brake on a slippery surface, the ABS activates and does whatever it does (I'm still not sure what that is - explained later.) What I've noticed is that the car seems to slide MORE than it would if the wheels just locked right up.

Am I not mistaken, or is the purpose of the ABS to pump the brakes at an extremely rapid rate, at different rates on specific tires, so that traction isn't lost and the best possible stopping distance on ice (or any slick surface) is maintained?

~ Brandon

[pickel]

ABS is designed to allow the best braking given the road surface and speed. My GMC truck..you could try to lock them up but the truck would just apply the cxorrect pressure to come to the best and fastest stop. If it sldes more than alockup , something is amiss in the system. I'd have it checked.

[brandon184]

We went for a drive with my friend's car, and noticed the same thing.

Maybe the conditions were a little more slick than we guessed? :P

~ Brandon

[Wizzard~Of~Ozz]

ABS is designed so you can continue to steer under slippery braking conditions, When it engages you may hear a vibrating sound. when this happens you have to put the petal to the floor as you might notice it goes limp. (If you are trying to stop quickly)

Personally I don't like ABS, but it might be handy on a corner with blackice. I don't like the limp petal thing but you really have to hammer on the brakes when it kicks in to stop quickly.

no ABS has a shorter stopping distance in 2 conditions which are similar, gravel and snow, no ABS plows into the snow/gravel stopping it faster, ABS pulsing doesn't allow the snow/gravel to accumulate infront of the tire, but you can turn if need be.

[brandon184]

.. Limp? My car (and my friend's Tiburon) is the complete opposite. The pedal goes completely stiff, and you have to put a lot of effort into pushing it down.

~ Brandon

[Wizzard~Of~Ozz]

How odd, the safari I used to drive went limp. same with the other astro's and an F150. always overshot stopsigns when it kicked in. (whew no cops ) You know what, maybe it wasn't limp more in-sensitive (been a while since I drove ABS vehicle).

[Sweeper]

My 2002 XLT 4x4 Ranger gets real stiff when braking hard as well. I've never felt the pedal vibrate since I've owned it and I too have noticed that sometimes it slides just about as much as my Mustang which didn't have ABS?

[OuTpaTienT]

Sounds to me like that ABS is working ok. That's exactly what it's supposed to do, tap or pump the brakes without allowing the tires to lock-up.

You're probably not old enough to remember, the rule of the road used to be "never do a panic-stop". A panic-stop is just jamming on the brakes with all your might. That's a big no-no with regular brakes because with the tires locked you have no steering control over the vehicle. Plus if you lock'em up at 60-70mph or above and keep'em locked until you stop, then you just ruined 4 tires as well by putting severe flat spots on all of them. (I've done it. )

Since ABS that "rule" has done a 180°. When driving vehicles with ABS then you SHOULD step on the brake with all your might, but the key difference now is while you do that you need to continue to steer the vehicle because you'll still have control thanks to no locked tires.

I guess depending on the exact situation it might be possible for a car with ABS to slide more, as you say. But I'd bet it just feels like you're sliding more. Truth is with ABS you shouldn't be sliding at all. Unless you're talking about lateral, or centrifugal force, as in sliding by turning...in that case it's poor driving, AKA driving too fast for the road conditions.

Here's what I read up on before I bought my new car with the ABS system:

http://www.nhtsa.dot.gov/cars/proble...absbrakes.html

http://www.autoshop-online.com/auto101/abs.html

http://www.howstuffworks.com/anti-lock-brake.htm