Bendix ABS-10

Thanks.

I take it, then, that I should try to get the dealer to condemn the whole unit to get it replaced under warantee?

You really need to take this to the dealer. Ever since the lifetime warranty/recall came out on that system, when people have had problems they have taken them to the dealers. As a result the independents seldom see them anymore. In fact the secondary market is flooded with bendix 10 manuals. The recall has also killed the reman/rebuild market for these.

In all liklihood, by the time you add in the credits that the warranty gives you, and subtract the usual overcharging over an independent that the dealer does, the cost to have a dealer fix it is probably going to be a wash with that of an independent anyway. (if the system wasn't warrantied and you took it to an independent, that is)

Put this down to a lesson, always research before buying used. The ABS system problems for these years are well documented and anyone with much experience with Chrysler minivans would have probably taken a pass on the van you bought, unless of course you got it at an absolute dirt cheap price.

Ted

Yer right.

But I'm an old dog (can't be taught new tricks) and haven't yet learned that the days of pulling a wet master cylinder and rebuilding it at home is no longer an option.

No such luck. It's gonna cost me $500. Dealer said they'd replace the whole unit for $1700.

Remember when a master cylinder rebuild kit cost $7.50?

Technology sucks!

Well, once you get the thing running and it saves your ass on a wet street, then come back and tell us how much better the 4-wheel drum brake setups are. ;-)

$500 isn't bad if the purchase price of the Caravan wasn't that high, and the body is straight.

Ted

It has drums at the rear anyway, which is no big deal as the rears do nothing but go along for the ride.

ABS will stop shorter than locked wheels, but longer than a properly modulated pedal. It is only handy for drivers that panic.

Yeah, other than the stoppers the van is in pretty good shape. It just grinds me that a system that should be - and can be - extremely simple and reliable is a monstrously complicated leaky unrepairable unreliable pos.

F1 is the most sophisticated automotive technology on the planet. Take a look at the brakes. Other than 4 pot calipers and carbon rotors, it's the same system I was racing with in the early '60s.

Technology sucks.

Except that only the best of professional race drivers can modulate their brakes with sufficient competence to beat ABS. And then only on a perfect surface. Put one side of the car on pavement and the other on wet pavement, snow, ice, etc. and ABS will win every time.

No, most technology is fine. Some isn't, but most is. What sucks is the fact that most people don't understand it.

Matt

Hardly. I'll train you to beat yer ABS in 15 minutes. And with practice, you'll never get into yer ABS again, even in a panic stop.

Go to an SCCA drivers school and watch the novices in street car classes where disabling the ABS is against the rules. The ones going deepest into the corners never activate the ABS.

ABS is like synchros, nice for the soccer moms but a waste for the drivers.

And it's expensive, overly complex, and of marginal value even to those that don't want to learn to drive.

Yes, and I suppose you could also adjust your spark advance faster than the computer controlled system, and you'd like to return to manual mixture controls and chokes...

I don't know if I can find it now, but I saw a test several years ago where lots of people said they could stop a motorcycle without ABS faster than one with ABS. They ran a test with several magazine editors who are all fairly proficient riders and a couple were regular racers. I believe that only one of the racers beat the ABS equipped bike and that was on dry pavement. Add in some water, sand, etc., and the ABS bike won EVERY time. And it won almost all of the time even on dry pavement.

I don't know if a similar test has been done with cars, but I'll bet the result would be the same.

And driving on a fairly smooth, dry, paved race track is nothing like driving in the real world with wet and oil roads, cases where one lane is dry and the other is black ice, etc. No human can beat ABS in these real conditions as you can't modulate each wheel separately as can the ABS system. So it matters not how much braking skill you have.

The only place I've seen, both from reading and from personal experience, where ABS falls short is in conditions of deep snow or very loose material like deep sand. In these situations, the locked tire is worse than "almost" locked tire, falls apart. If the tire is able to push up a mound of snow or sand by being locked, then the car will actually stop shorter. However, on most other surfaces a wheel that locks will lose traction compared to one at incipient lock-up.

Matt

Manual advance was replaced by mechanical (centrifugal) advance, which was simple, cheap, and reliable if you knew how to set yer timing and gap. Then came crank fire with simple, reliable electronics (the racers' choice was the Chrysler unit, btw). I'm not convinced that the ECU is any great leap forward, unless you are able to program it yerself.

I don't know anything about bikes, except that they stop on one wheel. Pass.

It's been done many times on cars, and ABS loses every time.

You haven't done much racing. We race in the wet. Oil (and coolant) and dirt/gravel is a constant hazard, and if you have both wheels on the pavement, yer not taking the corner right. Race cars (other than showroom stock, IT, and similar "street legal" classes) do not use ABS. Not in pro racing, not in Sunday afternoon amateur racing.

The justification for ABS is that it does work in an understeering car while cornering. On yer next trip to the grocery, watch the brake lights in front of you and you will see that most drivers turn in and apex far too early and continue to brake way beyond the apex, usually all the way to the exit of the turn. ABS works very very well under that condition. But ya don't have to be Sebastien Loeb to know that that's not how to go around corners. ABS is just a poor substitute for minimal driving skill.

Trouble is the optimum timing depends on more than just RPM. Yes, I know that there were also vacuum driven distributors to allow factoring in MP, but optimum timing depends on more than just RPM and MP. My point is that automatic controls, well designed, will beat a human every time. I don't if the automation is mechanical or electrical/electronic.

In the case of spark timing, since it depends on several factors, only two of which I mentioned above, electronic control is the way to go.

Do you have a reference? Under what conditions were the tests done? What was the skill level of the drivers?

Probably because the rules don't allow them. They've been introduced and subsequently banned in manner classes of racing, Formula One being an example. They gave too much of an advantage to the teams using them and the driver's machismo got in the way as well.

This is one of the best discussions I've seen on ABS systems.

I personally am not a big fan of them, but only because I live in a climate that has snow on the roads for 5 or so months each year. ABS is almost hazardous on snow, at least until you get used to it. The stopping distances of my minivans with ABS are much longer than my truck which has conventional brakes. On hard surfaces though, I've rarely noticed ABS being a handicap. And if you are really good at threshold braking, the ABS won't engage anyway so a really sharp driver won't even know it is there. And if they do feel it kick in, then they aren't as good at braking as they thought.

I'm not saying ABS is a substitute for better driving skills. I'm saying that ABS can do things that a human simply can't do, such as modulate the braking at each wheel independently to cover situations where each wheel is seeing a different mu. No way you can do that with one brake pedal. And if I gave you four brake pedals, you couldn't do it fast enough to be effective.

Matt

If you program it yerself, yes.

F1 has never used ABS. Traction control, which is a different beast, has been outlawed. ABS is allowed but not used in any other form of racing, to my knowledge. WRC uses very sophisticated traction control, but the handbrake overrides the TC. Most racers also use cockpit adjustable bias.

Driver's machismo? I've never seen a racer that would not jump at any chance for the slightest edge. And none use ABS.

It is a substitute for driving skills. ABS only works when the pedal is full on. Control of the braking function is given over 100% to the ABS. There are some things that a human can actually do better than electronics, and braking is one of them.

No argument there, I agree with that. My own van is Bendix 4 although I've never felt or seen the ABS come on. (my wife drives it mostly) My only beef is that Chrysler never released specs for it so OTC wasn't able to support Chrysler ABS in their scantool cartridges.

The Bendix 10 systems are very weird, must have been a junior engineer with no experience that did that design.

Ted