A friend of a friend (so I may not have all the details correct) recently hit someone who slammed on her breaks in front of him on the highway. He slammed on his breaks as well, but the ABS did not engage. He didn’t hear or feel it, and the car left a 45’ skid mark.
My question:
How common is ABS failure?
I couldn’t find any stats online. The car is a brand new Honda CRV.
Not an answer, not a criticism…but leaving a 45’ skid mark suggests a driver not trained to deal with locked brakes. Irrespective of whether the car has ABS, it’s a good idea to know about how rubber and tarmac behave when brought into intimate situations.
I cannot answer for Honda. On the cars I teach on the failure rate is >0, but is accompanied by a warning light AND a text message, plus a general caution light to warn the driver. Furthermore, the warning light is set up so that the normal condition of the light is on. Only when everything is OK, does the ABS system send a message that it is OK to turn the light off. This all OK message must be received on a periodic basis, or the instrument cluster will turn on the warning lights. In the event of a ABS system failure, or network communication failure all the warnings listed above will come on within a couple of seconds of the failure.
So on my car the chance of a ABS failure plus no notification to the driver is about as close to zero as you can get.
Now there is one other thing you might want to consider. About 8 years ago we did a track test of our sedans against sedans from Mercedes, BMW, Toyota, Lexus, Infiniti, and Honda. We ran these cars on a track to test their acceleration, handling and braking. A a group the cars from Japan had the most craptacular brakes you have ever seen.* People would get out of one of the European cars, get into one of the Japanese cars and going sailing off the end of the main straight. To be blunt the ABS systems on the Japanese cars sucked donkey balls.
Just because it says ABS on the trunk, does not mean it is a top flight system.
*Before all the owners of Japanese cars take me to the pit, this was 8 years ago, and we only tested one model from each car maker. Whatever you are driving might have as good an ABS system as my car. Then again it might not.
Oh, one more thing.
Your car has brakes. If they break, they are then broken, and you bring them to me to fix.
I recently had the pleasure of driving an Alfa 147 on the track (with ABS turned off), the brakes were incredible compared to my Toymotor Wish (small small MPV), not sure about the ABS system, but the brakes in the Alfa were way stronger.
I don’t think you’re going to find the statistics you seek, because I doubt that anyone compiles them. The closest you might get is numbers of ABS repair components sold, and you would probably have to track down every car manufacturer and aftermarket parts manufacturer to get those figures. Nevertheless, whether it’s common or not is a moot point. Either his ABS works properly or it doesn’t, and whether or not anyone else’s works or doesn’t has nobearing on that.
ABS is ONLY as good as the brakes you have! ONE big reason why German car’s brakes are so good: LARGER diameter rotors! ABS does NOTHING to help brake fading-which is cause by overheated rotors. Unfortunately, the japanese have taken a cue from GM-and use the smallest diameter rotors they can get away with (smaller rotors cost less). That is why the performance is inferior!
They might save a little cost, but not much…aside from the material cost, there is about as much manufacturing time and handling for big vs. small rotors.
Rotors are cast iron, or forged steel. They are very heavy, and big ones are heavier yet. Using smaller ones reduces the total weight of the car, (helping the CAFE numbers) and more importantly the unsprung weight at the wheel, which serves to improve handling and ride.
The National Highway Traffic Safety Administration would be a good place to start looking for this kind of information. Mosey on over to the Research tab, and then you can find Brakes on the left side of the page.
Possibly (though I didn’t see anything relevant there). But if they did have data, it would only be on recalls, which don’t necessarily relate to failures, and accidents, which only involve a portion of failures. As for the OP’s broad question “How common is ABS failure?”, I seriously doubt anyone has collected enough info to say. Almost anything along the same line - How common is horn failure? How common is water pump failure? - would face similar limitations. You can get seat-of-the-pants assessments from repair entities, you can (theoretically) get numbers of relevant parts sold, but who actually keeps any kind of list comprehensive enough to answer the question? No one I know of.
In addition, having bigger rotors means having bigger wheels, which may be a good or bad thing. If you need to buy winter wheels, probably bad.
Also, keep in mind that ABS brakes may actually take longer to stop straight on dry pavement than non-ABS (or Alphas with them turned off). I don’t have a cite, but a couple years ago I heard on CarTalk that there is a theory, Tom & Ray did not discount it at that time, that ABS is worse on dry pavement because it is in effect tapping the brakes, great for steering while braking, braking in wet, etc., maybe not so much for straight stop.
Right, a skillful driver can stop shorter than ABS brakes (even on wet pavement). However, most drivers aren’t at that level, and ABS lets them stop shorter while maintaining control* than they could without it.
*ABS stands for Anti-Blockier-System, which is German for Anti-Skid System. You can see why we didn’t make an acronym out of the English words. 
This is not necessarily a true statement. There is one and only one condition where you can flat make the statement that a non ABS car will out stop an ABS car. I will get to that in a minute.
When discussing stopping on dry pavement then: If, and I repeat if, you are working on a bottom of the line POS ABS system, you might be able to out stop it with a non ABS car when discussing stopping distances on dry pavement. However the chances are that the bottom of the line car that has a POS ABS system also has a POS hydraulic brake system, and POS tires. So you might not be able to. So if you compare say an old Corvette (No ABS, great big brakes, and wide tires) to the car with a POS ABS system you are for sure doing an apples to Porterhouse steak comparison. I mean come on here, you have tires that can pull almost 1.0G on the Vette and the POS has tires that can pull 0.6G. Only a moron would say the POS car could out stop the Vette. However, a moron might conclude that the ABS system is not as good as plain ole hydraulic brakes.
Now if you are talking about a car with a top of the line ABS system, I call bullshit. The cars I teach on can modulate the brakes 10-15 times per second, keeping the slip of the tires right at the point where braking is the most efficient. The tires on my cars will pull about 0.9G. That is the limiting factor when using the ABS for my car. The limiting factor is not the ABS system but rather the friction between the tire and road. Because the ABS can use 100% of the available friction between the tire and the road, there is no way to exceed that. Even if your brake system goes to 11. So getting back to what car talk said about ABS “tapping” the brakes. First of the system is not tapping the brakes; it is modulating them right at the point of lockup (where the most effective braking occurs). Even if you did care to refer to this as “tapping” who cares? The system is using 100% of the available friction between the tire and the road. That’s all there is, there ain’t no more. As long as I have 100% tire to road friction available to me, I don’t care if the ABS system does the Macarena. If anybody doubts this, swing by my training center and I will take you for a test drive and show you what a good ABS system can do. Then you are welcome to try to duplicate it after I disable the system. Loser buys the beer afterward.
So when can you out stop an ABS system? Sand, snow or gravel. Under these conditions, normal brakes will lock up and a mound of stuff will build up in front of each wheel. These piles of snow (sand, gravel) will help shorten stopping distance. With ABS, the wheels never lock, so the piles snow doesn’t accumulate and the stopping distance is increased somewhat. Early SAABS with ABS actually had an ABS defeat switch for driving in snow.
The down side of that shorter stopping distance is the fact that when you wheels are locked, you have no steering control. With ABS it takes longer to stop, but you can steer in the meantime.
friendlessboob The car talk guys are idiots. They have an entertainment program about cars. Every time I listen to them I find myself yelling CITE at the radio. Based on what I have heard them say on the radio, I would never take my car to them for repair. (Hell there are very few people I would take my car to, I guess I am picky)
Bah, I didn’t have my thread notifications set up right, so I thought everyone was ignoring the thread! Thank you all for the replies.
I have some more questions that I’ll ask later, but first, I am told that there was only one skid mark. That seems weird to me. I would think that if the ABS did not engage, then all the tires are pretty much guaranteed to skid. Is this correct? Maybe it’s independent for each tire, and only one failed? Any thoughts?
I’m not sure if all tires would skid if the ABS failed, but I would expect more than one to skid. Most systems do control each wheel independently, and it’s not uncommon to have a single wheel sensor, or single wheel control valve, fail. However, my understanding is that in such a case, the system’s self-checks would detect the fault and disable all ABS operation, as well as turn on the ABS light. And if somehow only one wheel wasn’t controlled (not likely but I wouldn’t say impossible) the driver should still be able to detect the system operating on the others. All things considered, it sounds like there was no ABS operation in the incident described.
On the mechanical side of things, sometimes a leaking wheel cylinder contaminates the rear brake shoes on one side only. That wheel’s brakes will then be squirrelly, sometimes grabbing and locking up. It’s quite unlikely on a new car, however.
If the car does indeed have ABS, I’d say registering a question/complaint at the dealership is called for.
Well this would be correct if each tire had exactly the same air pressure, had the same alignment, had shocks that were in exactly the same condition, the pavement was exactly the same on both side of the car, and the co-efficient of friction was exactly for all four wheels.
how often does this happen? It happened once in 1960 for twenty minutes. Now if you press hard enough, all four wheels will lock, but if you press just hard enough, only one wheel will leave a mark.
There is also one other point that has to be addressed:
There are skid marks
and there are
SKID MARKS
A car with ABS can and often will leave skid marks since the ABS is trying to keep the car on the verge of lock up, it is possible to leave a faint trail of black on the pavement. Accident investigators are now trained to be able to detect this faint marks to determine if a car braked before the accident.
As far as faults go, every ABS system I have seen will disable the entire system if there is a fault detected. not to say there isn’t one that goes into some type of limited operation, but I have never seen it.
Before yo go to the dealer, do this. Turn on the ignition, does the ABS warning light come on? If no, the bulb is burned out. If yes, start the car. Does the light go out? if yes, drive the car. If the light goes out and stays off, there probably is no fault with the system. Going after Honda in this case is probably a waste of time.
As Gary T pointed out earlier, ABS stands for Anti-Blockier-System which does not translate into bullet proof.
Is your part of your point basically that tires will lose adhesion even in the dry?
Since this zombie has been resurrected, I’ll share this anecdote: one way that ABS brakes can fail is on loose snow.
A couple of years ago, I tried to stop on 4-6 inches of untouched snow on an exit ramp that ended at an T-intersection. My anti-lock brakes activated, but failed to stop my vehicle. By the time I reached the end of the ramp, I was only going 5-10 mph, but the vehicle still failed to stop. I just glided on and on and on, until I slowly continued right through the intersection (which was clear, thankfully) and straight into a guard rail. I barely hit the guard rail, but it still took out a headlight, turn signal, and damaged the bumper – all in all, about $900 in repairs. :rolleyes:
After doing some research, it apparently is a known deficiency of ABS brakes. The ABS system tries to slow the car, but fails do so because there is zero traction. Ironically, if I could have turned off the ABS system and locked up the wheels, it would have built up a wedge of snow under each of the wheels (in a snowplow effect) that would have successfully stopped me.
The hand brake has no ABS usually, try that next time. If you can think of it in an emergency, which is admittedly hard.