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Last post Author Topic: Antilock-breaking (ABS) vs Stabilty Control (ESP) vs Traction Control Video  (Read 12983 times)

SeraphimLabs

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@SeraphimLabs - Are you psychic or something? If your posts got any closer to what is going through my head I'd have to start getting paranoid!

;) :D

Been fixing cars since I was old enough to hold a wrench. These days I mostly do industrial and IT related repairs, but I am around automation enough to always be second-guessing it and cross checking its behavior.

When you are around automatic stuff and it is your job to fix it, getting an inherent distrust of the machine is an occupational hazard. After all it is your job to find what is wrong with the device and put it right again.

Technology isn't some magic box that does stuff. It operates by a predictable set of rules. Watch its behavior until you learn the rules by which it works, and you can instantly spot when something has gone wrong with it.

Stoic Joker

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^Now I had me a funny feeling about that... :D :Thmbsup:

mouser

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So I took my car down a rocky gravely road, and tested ABS -- which kicked in easily on that surface.  It wasn't particularly dramatic but i'm glad to know what it feels like so if it happens in real driving it won't startle me.
I also tried to get it to trigger on a regular road, but a hard stop at 35mph did not trigger it -- despite giving me whiplash and throwing baby cody from the back seat to the front seat, and so i gave up on that.

IainB

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... It wasn't particularly dramatic...I also tried to get it [ABS] to trigger on a regular road, but a hard stop at 35mph did not trigger it -- despite giving me whiplash and throwing baby cody from the back seat to the front seat, and so i gave up on that.
______________________________
It shouldn't be obtrusive ("dramatic") if it is working properly. It's pretty much idiot-proof and doesn't require any special changes to your driving for it to work effectively. Just forget about it.***
Probably too much friction when you were on the dry road, so there would be no wheels locking up. Try it in the rain on the same road when it is wet and you will probably find it engaging. Try braking in the wet whilst you are turning and see what happens.
Then go and ask your insurers for a reduction in your car insurance premiums because, statistically, your chances of having an accident have been reduced by this technology. On the same principle, I was promptly given a 10% discount (after I had asked) by my AA (Automobile Association) Insurers on my annual all-risks car insurance when I passed the Institute of Advanced Motorists driving test (statistically, IAM members have a reduced risk rating - i.e., a lower risk profile).

***Note: But for goodness' sake remember it when you get in to drive a car that has no ABS fitted.
« Last Edit: June 15, 2014, 09:28:53 PM by IainB, Reason: Minor correction. »

IainB

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Anything I wrote above was based on the assumption that the ABS was fitted correctly and working properly.
However, I was alarmed to read in GM Recalls: How General Motors Silenced a Whistle-Blower:
Quote
...In May of that year, Kelley told lawyers, the audit found three problems, including a vehicle in Flint, Mich., with its antilock brakes improperly attached and a vehicle in Lansing with a fuel leak. McAleer’s lawsuit claimed that as much as 1 percent of all vehicles manufactured by GM during the 1999 model year could be defective, or more than 30,000 North American cars and trucks. ...
(My emphasis.)
Apart from the ABS problem, a 1% defective/unsafe ratio in car manufacture would seem to be a shockingly bad record. Furthermore, reading the article, one would probably have no way of knowing for certain whether they had fixed their QC processes, or just continued to bury the issue.
I'd think carefully before buying a car from that manufacturer, new or second-hand, without doing quite a bit of independent research first and giving the vehicle a complete independent AA safety inspection and certification before accepting delivery. Being paranoid about car safety and a bit of a petrol-head and a reasonable car mechanic, I'd also give it a thorough going-over myself, immediately after receiving it.

SeraphimLabs

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Well speak of the devil. Ruptured a brake line this morning.

Overshot slightly on a turn and hit the brake harder than usual to try and stick it anyway. Instead I get halfway into the turn, the brake goes soft, and I feel the car sliding sideways. Well riding it out was easy enough, it slid clear over into the other lane because of some loose stone and I had no problems correcting. Course when I reached the next stop sign I had a wait what moment- because my brakes weren't there.

Now if my car actually had ABS, that right there is where the automation would fail. It would sense that a line has ruptured and shut down in order to avoid wasting the remaining fluid. If you weren't used to driving without relying on the ABS, your brakes would suddenly become next to unusable. Fortunately I am familiar with utilizing engine braking to slow a vehicle with poor brakes, greatly reducing how much braking I have to perform. But again that's something most people don't do, that leads to accidents because they don't. They just rely on the car to work right all the time, which it won't.

IainB

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Scary. The only time I ever read of the actual hydraulic brake-line rupturing was when it got damaged on a loose stone road (a rally driver's curse), or in a minor shunt, or corroded. Do you inspect/check (or get checked) your vehicle every 6 months or so?

CWuestefeld

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A defective brake caliper about 25 years ago grabbed my disc and ripped itself off its mounting, thus opening the hydraulic line. That's the only time I've ever experience such, or heard of it happening.

It was quickly clear what had happened to the brakes. But note:
  • Once this happens, any rational person is going to drive very slowly and cautiously to the nearest service station, if not stop entirely. If at this point you get yourself into a situation where ABS would be required, you're beyond stupid.
  • When this happened to me, I still had partial braking. That's because car designs anticipates such a failure. You'll have two independent hydraulic "circuits", probably governing opposing wheels. So loss of pressure in one loses only half of your braking potential. I suppose that if I'd needed to drive more than 2 miles to get to service, the master cylinder might have run dry trying to push fluid into the broken line.
  • The vast majority of people today drive cars with automatic transmissions, which don't really afford a good means of engine braking.

SeraphimLabs

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  • The vast majority of people today drive cars with automatic transmissions, which don't really afford a good means of engine braking.
Have to disagree with you on this point.  Most automatic transmissions are provisioned to allow the driver to manually set it to a certain gear. That provision is meant for pulling trailers- and for engine braking. Just very few people know about or utilize that capability because engine braking is not taught in the normal driver's courses. I know about it from working farm tractors where engine braking is practically required due to the brakes on the tractor being too small for the tonnage behind it, but most people I talk to who haven't operated heavy equipment or big trucks have never heard of it. My current car has an automatic transmission, and not only have I heard it performing engine braking on its own while in cruise control, but I was successfully able to perform it using the manual override this morning to keep my speeds down and compensate for the loss of braking power.

I paid $1000 cash for this car about two years ago. Right from the start it needed new brakes, and one of the brake lines got changed at that time because I had to cut the line to get the caliper hose off. But for the most part the only time I even look at the underside of it is when I think there is something odd happening, and having the brake lines rot out and pop like this happens every couple years. I'm sure people who actually put money into their car to begin with would take the time and money to have it checked and repaired on the posted schedules, but most of the people I know don't bother - if it isn't broke don't fix it.

They do indeed use two circuits, but when you have a ruptured pipe every time you stroke the pedal you are shooting fluid onto the ground. So yes you can still stop, but you only can stop a couple of times before the shared reservoir has allowed all of the fluid to leave both systems. Driving it with a ruptured line should be avoided as much as possible for this reason.

Edit: And like clockwork, the line that I had to move aside to replace the one that failed just ruptured as well. Fortunately this one was in the driveway, pumped the brakes up real nice then rolled forward about 20 feet and stomped on it- squish as all the fluid runs out again. I hate cars so much.
« Last Edit: June 23, 2014, 01:58:41 PM by SeraphimLabs »

Stoic Joker

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I've been trying to find the time to finish this post for over a week!

So I took my car down a rocky gravely road, and tested ABS -- which kicked in easily on that surface.  It wasn't particularly dramatic but i'm glad to know what it feels like so if it happens in real driving it won't startle me.

That in itself is probably the most important - takeaway for you - part of the test. Because the last thing you need in an emergency situation...is more surprises.


I also tried to get it to trigger on a regular road, but a hard stop at 35mph did not trigger it -- despite giving me whiplash and throwing baby cody from the back seat to the front seat, and so i gave up on that.

Okay, I'm going to go out on a limb here, and assume you just gave the brake petal a good stomp to effect that reaction...yes? While it is excellent for testing purposes, It is also the exact type of problem behavior I was initially eluding to when one - fortified with ABS - takes the expression "Panic Stop" a bit too literally.

The reality of it is that in "normal" driving, if you really have to suddenly clamp down on the binders ... You weren't really paying attention. Otherwise, you'd have had other accident avoidance (e.g. escape) options available. And yes, after 35+ years of street riding this is where my motorcycling elitist background tends to bleed through rather quickly. Because for most people it's "just a fender-bender", but or me it could quite easily be a fatality ... Mine! ...So I tend to take that and the whole defensive driving thing quite seriously.

Now here is the part that people seem to have difficulty grasping. We've already had much discussion about ABS being able to stop a vehicle faster ... but the problem is - from a truly holistic defensive driving stand point - that's irrelevant. Because the real reason that ABS was originally explored as an option for cars, was to resolve an issue with steering control during hard breaking. Once the wheels lock due to excessive braking the ability the steer the vehicle is completely lost. That! is the one and only reason for ABS to ever be explored as a possible safety feature in an automobile. The fact that it also happened to make the cars stop faster by properly regulating break pressure was and still is a completely accidental (pun intended) fringe benefit.

Want proof, simple ... There are 2 wheel and 4 wheel designs for automotive ABS systems. Now for the 2 wheel only systems - on a 4 wheeled vehicle - which 2 wheels get the advantage of ABS control? I'll give you a (a slight misdirect) hint. Due to weight bias under breaking, the front wheels provide 70% of a vehicles stopping power. The ABS btw... goes on the back wheels. Why??? Steering control pure and simple. This configuration is actually most common in pickup trucks which when traveling empty and having no weight in the rear, have a very bad reputation of locking the rear wheels and sliding sideways.

Faster breaking...not so much. Safer breaking, yes ... But that - in defensive driving - is not necessarily always faster breaking. You see in defensive driving, the person who stops the fastest, is frequent also the first person to get killed in (if not the cause of) a chain reaction crash. First rule of defensive driving is in an emergency...look for a soft place to land.

Motorcycles stop faster than cars do - it's simple weight ratio physics. So I have always been able to stop much quicker then the folks in the cars around me. However... If the guy behind me can't stop as quickly as I'm about to...then who's fault is it really if he just so happens to run my stupid ass the fuck over? Hm..? Not really a trick question is it? I have to maintain steering control so I can swerve to some out of the way place - so as to politely and defensively allow him to proceed to continue and finish crashing into the idiot/obstacle that I just avoided. Otherwise to be brutally honest it is quite simply my own fault that he ran over my ass.

Now sure, Florida law says that if you rear-end someone, then the accident is automatically your fault. So according to 'The law' I would be completely blameless. However in any defensive driving classes you take the term applied to this type of situation is called being "Dead Right". Yeah, sure you're "right"...but you're also dead. Pyric victory anyone?

IainB

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...If the guy behind me can't stop as quickly as I'm about to...then who's fault is it really if he just so happens to run my stupid ass the fuck over? ...
^^ That!
I reckon right there is yet another example of why brakes were a ruddy dangerous invention in the first place. My old driving instructor always said that the risk of rear-end shunts would likely take a nosedive if cars were not fitted with hydraulic brakes. He said they were just not natural, and if you learned to drive the car without using them, then that was a huge economic saving as you wouldn't need to be worrying about the palaver and cost of servicing the unused hydraulic lines, brake shoes and disk callipers, and it was good riddance when the brake lines corroded - you could remove all the surplus deadweight of that paraphernalia and improve the car's power-to-weight ratio.
And as for engine-braking, I recall him saying that it was to be avoided at all costs, as, not only could it make for really jerky driving and risk hurting passengers' necks, but also, with constant use, it would destroy the transmission as you were making it do something it was not designed to do (it was designed to transfer the engine's energy to push the car forwards, not slow it down). My instructor felt so strongly about this that he always had the reverse gear in his cars disabled by having the reverse cog removed from its gearshaft. That way, he reckoned his gearbox would last a lot longer, without all that unnatural grinding and wear and tear. I reckon he had a point.

I often think of him. He taught me all I know about driving, though I haven't driven for the years since as my eyesight was too bad to get me a driving licence. I was sad to hear a couple of years ago that he had been killed in an unfortunate accident in our small home town. Apparently, he had slammed into the back of a school bus that had stopped in a hurry to avoid running over a child crossing the road. I went to the funeral, and found I was the only one of his thousands of ex-pupils to attend, as they had all pre-deceased him. Would you believe it?
« Last Edit: June 23, 2014, 10:42:08 PM by IainB »

Stoic Joker

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 :-\ ... You're screwing with me, aren't you? :D

IainB

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We...erm...you are a Stoic Joker after all - right?     ;)
But not just you. This thread.

mikiem

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From an old mechanic/street racer perspective...

Cars are designed purely so people will buy them, with the over-riding principle of cost savings to the manufacturer. Many times when you read about [or heaven forbid experience] some rather drastic problem with a car or truck, it's because someone decided to save $, sometimes as little as a penny, maybe even less.

Understanding that is important in two main ways or aspects... Features like you're discussing, ABS etc., are not designed to work optimally, but rather so that the people making up the target market for whatever car/truck like it. Automotive engineers have come up with countless improvements over the decades, some of which really could have made a very big difference in safety &/or performance, but they never saw production because the target market didn't approve. AND when features are included, 90+% of the time they are not as effective or reliable as they could be.

The performance & reliability of ABS, stability & traction control depends on the vehicle -- it's usefulness further depends on the driver -- how to best utilize any of the 3 depends on the vehicle, driving conditions, & the driver. All 3 are there because tires will lose traction with the road, and most all cars [& all trucks] are Not designed for handling, or put another way, are Not designed to maintain traction. And most people have better things to do or are not inclined to try to become race car drivers. :)

Give up ground clearance & a soft ride, pay the cash for better tires, if you can find one get a car with 4 wheel steering [e.g. Honda's simple system that wouldn't sell in the US], & have/use the modern equivalent to the old positraction. Then spend time playing in an empty parking lot or similar & find your car's limits, & how best to handle them. A *good* ABS system might be worthwhile, but the other 2 would be pretty much senseless. They're band-aids for less practical design & well, frankly a result of the car or truck you chose to buy.

I'm not saying don't buy a SUV for example -- I'm trying to put it in perspective, saying that attempting to compensate for less than optimal design [& perhaps driving skills] is going to have limits & will never be the absolute best answer. I'd prefer the idiots we all encounter on the road had all 3, out of a sense of self preservation. With the exception of a *good* ABS setup, I don't believe automated systems can ever do as well as a highly skilled human -- that's what I have against the Google cars -- because the possibilities that can be encountered are almost infinite, while forethought designing this stuff & writing code are definitely finite. :)

Stoic Joker

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I like ^this guy! :Thmbsup:

mikiem

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My current car has an automatic transmission, and not only have I heard it performing engine braking on its own while in cruise control, but I was successfully able to perform it using the manual override this morning to keep my speeds down and compensate for the loss of braking power.

Automatic transmissions use a torque converter -- oversimplified imagine two propellers in a liquid, one powered, & the other connected to the transmission. A locking torque converter [which most vehicles have nowadays] tries to do just that, lock at higher speeds. A manual transmission uses a clutch, where a disc with a material similar to brake lining on both sides is squeezed by spring tension between the engine's flywheel & the transmission's input shaft. When you step on the clutch pedal you release that spring tension -- the more you press down the more spring tension is reduced.

So... you should be able to see or imagine why a torque converter might be less ideal for downshifting &/or braking. Will it work? Yes, but it's better suited to limiting the gear to a lower range, limiting speed going downhill in the mountains.

Quote
We've already had much discussion about ABS being able to stop a vehicle faster ... but the problem is - from a truly holistic defensive driving stand point - that's irrelevant. Because the real reason that ABS was originally explored as an option for cars, was to resolve an issue with steering control during hard breaking. Once the wheels lock due to excessive braking the ability the steer the vehicle is completely lost.


ABS attempts to stop a skid -- sometimes, in some conditions, releasing & reapplying the brakes *may* help, by essentially giving the tires a 2nd, 3rd etc. chance to grab. For it to work traction must already be lost. Skids can be intentional, sometimes directed, sometimes controlled, and skids to some extend can often be countered. Control is not always completely lost, though it requires the driver not panic, & it obviously helps of they've prepared themselves beforehand, e.g. by practicing to know their vehicle's characteristics & limits.

I do agree about defensive driving, but wanted to mention personal responsibility as well -- it is the driver's responsibility to make sure the vehicle they're driving is operating optimally & is well maintained. People skimp on brake work, & they skimp on tires, & most don't research either the same way they might research say a video card.

Quote
Due to weight bias under breaking, the front wheels provide 70% of a vehicles stopping power

Basic physics really -- the best example I can think of is when you lock front & rear brakes on a bicycle, & if you were going fast enough the rear tire will come off the ground. Momentum carries the total mass forwards, while the stopping point is where the tires meet the road or ground -- that's where the center of gravity comes in, the lower the better. The suspension, when there is one, matters too -- the more the nose can dive because of suspension travel, the more the nose will dive, the more the problem is pronounced.

Regardless the front wheels have always been where the majority of the stopping power is, with the rear brakes almost entire purpose keeping you stopping in a straight line -- that's why so many cars & trucks have front discs but rear drum brakes. [BTW, many rear drum brakes are Only adjusted when you use the parking or hand brake. And yes, drum brakes Have to be adjusted.]

Quote
Florida law says that if you rear-end someone, then the accident is automatically your fault.

Ahh, but did you know FL traffic laws also favor direction, as in North or South? I got broadsided at a 4-way stop. Traditional common sense would say that they idiot who hit me was at fault, but in FL, Not So. That everyone was at a complete stop was never in dispute -- that I got there 1st was never in dispute. But because I was traveling East->West [as far as I can remember] the idiot who hit me had the right of way!

Quote
And as for engine-braking, I recall him saying that it was to be avoided at all costs, as, not only could it make for really jerky driving and risk hurting passengers' necks, but also, with constant use, it would destroy the transmission as you were making it do something it was not designed to do (it was designed to transfer the engine's energy to push the car forwards, not slow it down).


May sound logical to someone without mechanical knowledge, but say that to a decent mechanic to make him/her laugh. Did he know how unnecessarily hard it would be to manufacture gears that had only one face of the teeth hardened?

mikiem

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Right from the start it needed new brakes, and one of the brake lines got changed at that time because I had to cut the line to get the caliper hose off. But for the most part the only time I even look at the underside of it is when I think there is something odd happening, and having the brake lines rot out and pop like this happens every couple years.

What you need to consider is total age & condition plus the possibility of contaminants. If one PC case fan goes out, myself I'll replace all the others that are the same age rather than assume it was a fluke. If one rubber brake line rotted, assume all are the same age & replace them. BTW, heat + penetrating oil + a crows foot type fitting socket connected to a small impact help loosen rusted fittings. The impact can be key because of the rapid impacts -- not raw horsepower.

I mentioned contaminants... ANYTHING but pure brake fluid [of the correct type for your car/truck] can trigger chemical reactions that will swell &/or eat rubber seals & lines. THIS IS IMPORTANT. Rubber lines rarely go bad -- I can't remember replacing one in years running dealer service. It could be a combination of age & environment, e.g. in the Detroit area winter road salt wrecks havoc, but if you're repeatedly having problems with rubber lines consider the possibility that water or something else has gotten into the brake fluid, &/or that the wrong type of fluid has been added. I have seen where that led to ONE of the brakes locking on -- at high speed! Imagine what happens when a wheel stops turning!

SeraphimLabs

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My current car has an automatic transmission, and not only have I heard it performing engine braking on its own while in cruise control, but I was successfully able to perform it using the manual override this morning to keep my speeds down and compensate for the loss of braking power.

Automatic transmissions use a torque converter -- oversimplified imagine two propellers in a liquid, one powered, & the other connected to the transmission. A locking torque converter [which most vehicles have nowadays] tries to do just that, lock at higher speeds. A manual transmission uses a clutch, where a disc with a material similar to brake lining on both sides is squeezed by spring tension between the engine's flywheel & the transmission's input shaft. When you step on the clutch pedal you release that spring tension -- the more you press down the more spring tension is reduced.

So... you should be able to see or imagine why a torque converter might be less ideal for downshifting &/or braking. Will it work? Yes, but it's better suited to limiting the gear to a lower range, limiting speed going downhill in the mountains.

And this is one place that automation can improve considerably. On a vehicle where the PCM is able to recognize when engine braking is about to take place, the torque converter can be instructed to lock up and stay locked once the transmission is in a suitable gear. I suspect my car is able to do this, since I've seen it engine braking all by itself while in cruise control and going down a steep hill.

Like so, engine braking with an automatic transmission is as practical as it is on a manual transmission, because the only difference between the two is the slightly higher slip factor resulting from the design.

Designs that don't do that though, you are indeed correct that engine braking with an automatic is less effective than on the same vehicle equipped with a manual transmission. Usually you end up going a gear or two lower into the range of options with an automatic in order to bring the RPM up enough to make the torque converter couple it back to the engine.

Quote
And as for engine-braking, I recall him saying that it was to be avoided at all costs, as, not only could it make for really jerky driving and risk hurting passengers' necks, but also, with constant use, it would destroy the transmission as you were making it do something it was not designed to do (it was designed to transfer the engine's energy to push the car forwards, not slow it down).


May sound logical to someone without mechanical knowledge, but say that to a decent mechanic to make him/her laugh. Did he know how unnecessarily hard it would be to manufacture gears that had only one face of the teeth hardened?

There actually is a mechanical concern to engine braking an automatic now that I think about it. It has to do with the way automatic transmissions shift- using bands similar to brake pads to grab different areas of the planar assembly in order to change the gear ratio without ever actually meshing or unmeshing the gears.

If you apply too much torque to this assembly, it can cause the bands to slip. This results in increased transmission wear and heating, and could indeed ruin the transmission.

However, this only applies to automatic transmissions, and really is only a concern in a scenario where the transmission is already worn out to a point where it is already experiencing internal slippage problems. A transmission that still has plenty of band-meat left and is operating at or above its optimum shifting pressure will have sufficient resistance to internal slip that engine braking won't hurt it any more than smoking the tires at the redlight- because again the tires will lose traction long before anything bad happens mechanically inside the transmission.

Quote
Right from the start it needed new brakes, and one of the brake lines got changed at that time because I had to cut the line to get the caliper hose off. But for the most part the only time I even look at the underside of it is when I think there is something odd happening, and having the brake lines rot out and pop like this happens every couple years.

What you need to consider is total age & condition plus the possibility of contaminants. If one PC case fan goes out, myself I'll replace all the others that are the same age rather than assume it was a fluke. If one rubber brake line rotted, assume all are the same age & replace them. BTW, heat + penetrating oil + a crows foot type fitting socket connected to a small impact help loosen rusted fittings. The impact can be key because of the rapid impacts -- not raw horsepower.

I mentioned contaminants... ANYTHING but pure brake fluid [of the correct type for your car/truck] can trigger chemical reactions that will swell &/or eat rubber seals & lines. THIS IS IMPORTANT. Rubber lines rarely go bad -- I can't remember replacing one in years running dealer service. It could be a combination of age & environment, e.g. in the Detroit area winter road salt wrecks havoc, but if you're repeatedly having problems with rubber lines consider the possibility that water or something else has gotten into the brake fluid, &/or that the wrong type of fluid has been added. I have seen where that led to ONE of the brakes locking on -- at high speed! Imagine what happens when a wheel stops turning!

I've never seen rubber brake lines. Its always steel, sometimes copper or plastic coated in a futile attempt to stop them from rotting out so fast. If only I could get stainless steel brake lines without breaking the bank, they'd stay pristine for the entire lifetime of the car.

Usually whenever I have to work on the brakes at all, I'll bleed the system down to nothing and refill it with fresh fluid from a sealed container. Contaminants eat calipers and master cylinders, and even if you keep the system tight they still manage to get in there. Fluid is cheap, and if it keeps me from having to change anything more expensive than the lines I don't mind paying that much.

Money is tight for me though. Simply replacing things whenever I happen to think about it would leave me completely broke. Though I prefer to not have it break in the first place, when you're limited on cashflow its best to stick to if it ain't broke don't fix it. And then make a point of learning how to ride out any failures that do happen, cause it will break no matter what you do it.

Stoic Joker

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Florida law says that if you rear-end someone, then the accident is automatically your fault.

Ahh, but did you know FL traffic laws also favor direction, as in North or South? I got broadsided at a 4-way stop. Traditional common sense would say that they idiot who hit me was at fault, but in FL, Not So. That everyone was at a complete stop was never in dispute -- that I got there 1st was never in dispute. But because I was traveling East->West [as far as I can remember] the idiot who hit me had the right of way!

Hmmm... I'm not so sure about that bit. The only fine print in FL law about intersections is that if two people stop at the exact same time, the person on the right has the right of way.


I've never seen rubber brake lines.

There's always that last bit that goes from the axel to the chassis (rear) or the chassis to the wheel (front) where the suspension travel requires it to be flexible.  :)

40hz

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ABS attempts to stop a skid -- sometimes, in some conditions, releasing & reapplying the brakes *may* help, by essentially giving the tires a 2nd, 3rd etc. chance to grab. For it to work traction must already be lost. Skids can be intentional, sometimes directed, sometimes controlled, and skids to some extend can often be countered. Control is not always completely lost, though it requires the driver not panic, & it obviously helps of they've prepared themselves beforehand, e.g. by practicing to know their vehicle's characteristics & limits.


+1

I've generally found the ABS feature on Fords to be more startling for the driver than actually useful. I'm a big believer in anticipating and preparing in advance whenever possible. As the Top Gun school allegedly says: You don't rise to the occasion - you default to your level of training. So first snowfall, I make it a point to get a little "skid practice" as soon as I'm in a safe place to do it. Especially since people seem to be stupidest after that first coating of snow. After they get some experience with it over the following day or two, 90% are fine. So the sooner you're prepared the better off you are.

Same goes for a 'new' car. An empty lot and a spare hour getting a real feel for the individual vehicle is time well spent.

Stoic Joker

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ABS attempts to stop a skid -- sometimes, in some conditions, releasing & reapplying the brakes *may* help, by essentially giving the tires a 2nd, 3rd etc. chance to grab.

...Unless the "skid" (acceleration or deceleration) has gone past 45 degrees to the direction of travel...then you're stuck riding-it-out to avoid high-siding.


Skids can be intentional, sometimes directed, sometimes controlled, and skids to some extend can often be countered. Control is not always completely lost, though it requires the driver not panic, & it obviously helps of they've prepared themselves beforehand, e.g. by practicing to know their vehicle's characteristics & limits.

+1 - While I've never really grocked drifting (e.g. how much is too much/I'm getting old), I am notorious for flat-tracking a full dressed Harley around corners. Practice, practice, know beats the hell out of guess, hope, and die any day of the week. :D