ABS question, mechanically oriented.
#21
Guest
Posts: n/a
Re: ABS question, mechanically oriented.
"C.R. Krieger" <warp2_shadowMAPS@yahoo.com> wrote in message
news:3fe06f4c$0$40211$39cecf19@news.twtelecom.net. ..
> "Hairy One Kenobi" <abuse@[127.0.0.1]> wrote in message
> news:aorDb.4179$526.28889@newsfep4-glfd.server.ntli.net...
> >
> > (Quite apart from that, if a caliper "sticks" then it's more likely to
be
> in
> > the retracted position, IMHO)
>
> Respectfully disagreeing, IME, there's always enough hydraulic pressure to
> push the pistons *out* and very little in terms of piston seal flex to
bring
> them *back*. That's why the simplest visual indicator of a stuck piston
is
> excessively worn pads on that wheel.
Fair enough - I've only ever seen the converse (usually down to corrosion on
a car that's been stood "for a while"). Particularly the sliding type at the
rear (e.g. Ford Sierra Cosworth)
Mind you, I'm also having difficulty understanding how someone wouldn't
/notice/ one of their brakes jammed on (two, I can understand, but one..!)
I take your point, though.
H1K
news:3fe06f4c$0$40211$39cecf19@news.twtelecom.net. ..
> "Hairy One Kenobi" <abuse@[127.0.0.1]> wrote in message
> news:aorDb.4179$526.28889@newsfep4-glfd.server.ntli.net...
> >
> > (Quite apart from that, if a caliper "sticks" then it's more likely to
be
> in
> > the retracted position, IMHO)
>
> Respectfully disagreeing, IME, there's always enough hydraulic pressure to
> push the pistons *out* and very little in terms of piston seal flex to
bring
> them *back*. That's why the simplest visual indicator of a stuck piston
is
> excessively worn pads on that wheel.
Fair enough - I've only ever seen the converse (usually down to corrosion on
a car that's been stood "for a while"). Particularly the sliding type at the
rear (e.g. Ford Sierra Cosworth)
Mind you, I'm also having difficulty understanding how someone wouldn't
/notice/ one of their brakes jammed on (two, I can understand, but one..!)
I take your point, though.
H1K
#22
Guest
Posts: n/a
Re: ABS question, mechanically oriented.
"Hairy One Kenobi" <abuse@[127.0.0.1]> wrote in message
news:mC_Db.5049$FN.1613@newsfep4-winn.server.ntli.net...
> "C.R. Krieger" <warp2_shadowMAPS@yahoo.com> wrote in message
> news:3fe06f4c$0$40211$39cecf19@news.twtelecom.net. ..
> >
> > That's why the simplest visual indicator of a stuck piston is
> > excessively worn pads on that wheel.
>
> Fair enough - I've only ever seen the converse (usually down to corrosion
on
> a car that's been stood "for a while"). Particularly the sliding type at
the
> rear (e.g. Ford Sierra Cosworth)
If it's been *sitting* for a long time, you're correct. They can get stuck
*in*, but a hefty push on the pedal will usually dislodge them (thus getting
them stuck *out*! ;^) ).
> Mind you, I'm also having difficulty understanding how someone wouldn't
> /notice/ one of their brakes jammed on (two, I can understand, but one..!)
A couple of things. In the rear, you'd only notice a slight drag. In the
front, if the car's got a negative scrub radius (IIRC, Audis do), then you
*also* might not notice.
--
C.R. Krieger
"Ignore 'em, m'dear; they're beneath our dignity." - W.C. Fields
news:mC_Db.5049$FN.1613@newsfep4-winn.server.ntli.net...
> "C.R. Krieger" <warp2_shadowMAPS@yahoo.com> wrote in message
> news:3fe06f4c$0$40211$39cecf19@news.twtelecom.net. ..
> >
> > That's why the simplest visual indicator of a stuck piston is
> > excessively worn pads on that wheel.
>
> Fair enough - I've only ever seen the converse (usually down to corrosion
on
> a car that's been stood "for a while"). Particularly the sliding type at
the
> rear (e.g. Ford Sierra Cosworth)
If it's been *sitting* for a long time, you're correct. They can get stuck
*in*, but a hefty push on the pedal will usually dislodge them (thus getting
them stuck *out*! ;^) ).
> Mind you, I'm also having difficulty understanding how someone wouldn't
> /notice/ one of their brakes jammed on (two, I can understand, but one..!)
A couple of things. In the rear, you'd only notice a slight drag. In the
front, if the car's got a negative scrub radius (IIRC, Audis do), then you
*also* might not notice.
--
C.R. Krieger
"Ignore 'em, m'dear; they're beneath our dignity." - W.C. Fields
#23
Guest
Posts: n/a
Re: ABS question, mechanically oriented.
Bascally you have a powerful motor that is pushing UP on your brake pedal
for 1/25th of a second allowing the wheel to turn, then allowing your brakes
to lock again due to your foot pressure. These have been in cars since
1993.
"Grover" <ccleaveland@earthlink.nospam.net> wrote in message
news:BBFE0ED0.4D1B%ccleaveland@earthlink.nospam.ne t...
> Just after reading some of the debate on a recent/current ABS thread, I
went
> out and jumped on my brakes on a wet road with a slight curve. (I won't
say
> whether it was planned or not.)
>
> The anti lock system activated, and I came to a controlled stop.
> Let's just say it was exciting.
>
> Now my question: The pedal feeling and sounds are so rapid and violent,
> like a small machine gun, that I can't help but think that it's wearing
> something out pretty rapidly. Is it?
>
> The modulator valves? The hydraulic brake line fittings? Nothing?
>
>
> Thanks,
>
> Grover
>
for 1/25th of a second allowing the wheel to turn, then allowing your brakes
to lock again due to your foot pressure. These have been in cars since
1993.
"Grover" <ccleaveland@earthlink.nospam.net> wrote in message
news:BBFE0ED0.4D1B%ccleaveland@earthlink.nospam.ne t...
> Just after reading some of the debate on a recent/current ABS thread, I
went
> out and jumped on my brakes on a wet road with a slight curve. (I won't
say
> whether it was planned or not.)
>
> The anti lock system activated, and I came to a controlled stop.
> Let's just say it was exciting.
>
> Now my question: The pedal feeling and sounds are so rapid and violent,
> like a small machine gun, that I can't help but think that it's wearing
> something out pretty rapidly. Is it?
>
> The modulator valves? The hydraulic brake line fittings? Nothing?
>
>
> Thanks,
>
> Grover
>
#24
Guest
Posts: n/a
Re: ABS question, mechanically oriented.
Mike writes:
>These have been in cars since
>1993.
Uhhhhh, you're about ten years late. I was driving abs in 1986.
Dave
http://hometown.aol.com/davplac/myhomepage/index.html
>These have been in cars since
>1993.
Uhhhhh, you're about ten years late. I was driving abs in 1986.
Dave
http://hometown.aol.com/davplac/myhomepage/index.html
#26
Guest
Posts: n/a
Re: ABS question, mechanically oriented.
"Dave LaCourse" <davplac@aol.comPirate> wrote in message
news:20040106214404.11003.00001426@mb-m24.aol.com...
> Forgot to add..... abs was around before that (1986).
Jensen FF, 1966. Also the first production road car with AWD and traction
control, IIRC.
H1K
news:20040106214404.11003.00001426@mb-m24.aol.com...
> Forgot to add..... abs was around before that (1986).
Jensen FF, 1966. Also the first production road car with AWD and traction
control, IIRC.
H1K
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