#192128 - 12/30/09 12:06 AM
anti lock brakes question
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Cranky Geek
Carpal Tunnel
Registered: 09/08/05
Posts: 4642
Loc: Vermont
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OK, I'm going to sound really dumb and naive with this one, I know it, but if Raven can't swallow his pride at ETS, there is no place where I can.
Breaking for a light tonight, I had my break pedal pump back at my foot. Roads suck, so I was giving it a lot of time but it was still a close thing. Now, this wasn't a little bit of a tap that I knew it was there, but it felt like a 4-5mm push back at my foot just before I started to really get traction.
Is this normal? The Escape is the first car I've ever owned that didn't suck, so I know a lot about what feels "right" when it is wrong, so I could just be being paranoid. Or do I have a problem?
_________________________
-IronRaven
When a man dare not speak without malice for fear of giving insult, that is when truth starts to die. Truth is the truest freedom.
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#192131 - 12/30/09 12:29 AM
Re: anti lock brakes question
[Re: MDinana]
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Pooh-Bah
Registered: 11/25/08
Posts: 1918
Loc: Washington, DC
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The few times I've slammed on ABS, it's been a weird sensation.
I'd have thought something was broken if I didn't know about the ABS.
Started out on and drove a 1969 Mustang for 14 years, so ABS was a big difference.
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#192132 - 12/30/09 12:30 AM
Re: anti lock brakes question
[Re: ironraven]
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Geezer
Registered: 06/02/06
Posts: 5357
Loc: SOCAL
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Sounds normal. I don't know about the 4-5mm part, but AFAIK push back when the ABS pulses is normal.
_________________________
Better is the Enemy of Good Enough. Okay, what’s your point??
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#192133 - 12/30/09 12:32 AM
Re: anti lock brakes question
[Re: ironraven]
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Pooh-Bah
Registered: 09/01/07
Posts: 2432
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Without experiencing it first hand it is hard to say for sure but the general description you give sounds like a fair description of what I have experienced as the ABS kicks in.
I grew up when you controlled a skid by steering into it and pumping the brakes. I thought I was pretty good at it and enjoyed being able to trigger the start and stop of a four-wheel drift with a fair bit of precision using the steering and accelerator. Pumping the bakes was just part of the package of what it meant to be a skilled driver.
Of course ABS changed all that. I felt special in may ability to effectively pump the brakes to control a skid and limit stopping distance. ABS took all that away. The engineering says the ABS control system can do a much better job of it. Applying the brake selectively with millisecond timing. My roll is reduced to stomping on the brake. That doesn't make me any happier.
And it feels odd to be having the pedal pumping itself under my foot. Another useful and valuable human skill, a way for a person to set themselves apart and earn a living, reduced to an anachronism.
I see the same thing when I go shopping. Used to be cashiers were required to punch in prices. Many had to pass a nine-key speed and accuracy test. And if you could you were more valuable to an employer and made more money. In a day when minimum wage was close to $2 a nine-key trained person could make $.50 to $1 an hour more. Big money in that day.
Laser scanners did away with that. Now pretty much anyone above room temperature can run a cash register. And cashiers make no more than any other employee.
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#192134 - 12/30/09 12:50 AM
Re: anti lock brakes question
[Re: Art_in_FL]
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Cranky Geek
Carpal Tunnel
Registered: 09/08/05
Posts: 4642
Loc: Vermont
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Thanks guys! Lot less freaked.
It FELT like 4-5mm. Considering this was the biggest kickback I've ever felt from my car when I wasn't hitting something *blush* it probably was half that. It was one of those "ah, hell" moments, because if I didn't stop, I at least had a clear shot all the way down to the lake. I was pretty sure that if I didn't get hung up, the lake was going to stop me. *laughs*
Still need to get proper tires on it. I've found a lot of places with three (3) snow tires for non-obscene amounts. How do you get three snow tires? Are they ordered in multiples of five? Are there that many people who want a spare winter tire?
And Art, I agree with you about the pumping the breaks thing, at least emotionally. But I also know that a controls with feedback sensors are faster than we are. Tell a computer "do everything you can not to die" and it will do at least a good a job as we will, if not better.
_________________________
-IronRaven
When a man dare not speak without malice for fear of giving insult, that is when truth starts to die. Truth is the truest freedom.
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#192139 - 12/30/09 02:04 AM
Re: anti lock brakes question
[Re: ironraven]
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Carpal Tunnel
Registered: 12/26/02
Posts: 2997
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Yea, sounds like ABS. I know people say ABS can read the sensors faster than we can but the brake pads can only move so fast. I've also found every one I've ever driven to be way too sensitive, it will engage way too soon. I tested out one time by braking in an empty parking lot with and without ABS (pulling the fuse) and I could beat ABS every time and I don't have the best of reflexes. This was a year 2000 truck with three channel ABS so both rear wheels shared a sensor. I still prefer the poor mans ABS where you have a true 4x4 with lever shift and to lock the front and back and a manual transmission, basically a wheel on one end can't stop spinning to skid because a wheel on the other end as well as the engine is still turning thereby forcing the wheel that might have skidded to keep turning. I was driving home late one night from work when I went up the raised roadway over the highway and saw the police directing traffic and stopping cars getting on and off the highway because the ones coming over the hill were going through the intersection, sliding or ABS preventing them from stopping. The police saw me coming and stopped traffic then I just down shifted through the gears, got in the left turn lane and slowed down pushed the clutch and braked the last second to a stop. I think the policeman smiled as he waved me through the left turn as the cars in the straight lanes beside skidded on through the intersection.
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#192141 - 12/30/09 02:45 AM
Re: anti lock brakes question
[Re: Eugene]
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Old Hand
Registered: 03/24/06
Posts: 900
Loc: NW NJ
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ABS annoys me. ABS is to stopping as a differential is to acceleration. The wheel with the least traction dictates the effective traction of each of the other wheels.
Thus when one wheel hits a patch of ice just as you roll up to a stop sign, the brakes on the other three wheels release and you skitter into the intersection, because God forbid that one wheel should skid a little.
So in many situations ABS does not stop you in the shortest distance. What it does do is help keep you going straight. A good driver can modulate the brakes and stop quickly without spinning out, but it takes skill. The average idiot just mashes down on the brakes anyway, so ABS is helpful to him.
The lowest common denominator strikes again.
IR, I suggest you take your car to a nice empty parking lot the next time it snows and get some practice with how it responds.
_________________________
- Tom S.
"Never trust and engineer who doesn't carry a pocketknife."
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#192143 - 12/30/09 03:30 AM
Re: anti lock brakes question
[Re: thseng]
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Pooh-Bah
Registered: 09/01/07
Posts: 2432
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My present vehicle is a pickup truck and it has ABS only on the rear wheels. It makes some sense because the rear wheels on your typical PU are very lightly loaded if your not carrying a load so there is a tendency for the rear wheels to lock up and slide.
The same thing is true on tractor-trailers if they are not carrying a load. I've seen them sliding, smoking and squealing if the trucker tried to stop too fast. Newer trucks have ABS.
The ABS on my truck is pretty primitive. ABS on newer vehicles is smoother and faster.
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#192148 - 12/30/09 06:50 AM
Re: anti lock brakes question
[Re: Art_in_FL]
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Crazy Canuck
Carpal Tunnel
Registered: 02/03/07
Posts: 3239
Loc: Alberta, Canada
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ABS annoys me too -- I grew up in the era where real men (and women) knew how to pump their brakes, while dropping the automatic into neutral or gently engaging the clutch in a lower gear.
[pauses to pound chest ... and remember the good old days]
That has passed. In all honesty I must confess: even the crudest ABS pumps 5-10 times faster than I could manually. On an icy road, downshift gently and let the engine slow you down, then if necessary punch those ABS brakes and hold 'em. Your job is to steer ... toward the curb where the road is less polished; or straight into the snow-filled ditch; just don't hit another car or a whole 'nother bunch of ugly kicks in.
Yup, basic ABS kicks the pedal. But the bottom line is: ABS works.
Edited by dougwalkabout (12/30/09 06:52 AM)
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