Interesting ABS problem
 

'96 Accord EXR, VTEC

Hi again, My ABS is acting strangely. Recently, I noticed a peculiarity when
coming to a stop: the ABS kicks in momentarily. To be more specific, when
stopping with light brake pressure only, just before the car is completely
stopped, the ABS releases the brake pressure and then re-applies it. This
makes the car lose deceleration and then stop suddenly. IT only does this
when using light brake pressure and at very slow speeds. However, the
problem is significant enough to be potentially dangerous. If I am pulling
my boat for example, I can easily misjudge where the car will halt be a foot
or more.
At first I thought this was related to another problem I had recently where
one of my brake calipers came loose ( on the back of the car ); I guess I
used to much anti-seize and didn't torque down the nuts enough. But this is
definitely an ABS problem. I know this for certain because if I engage my
hand-brake just enough to make the warning light come on, after about a
minute or so, the ABS will shut off, as indicated on the dash. I know this
to be normal. The symptoms during a stop are no longer. Releasing the hand
brake and having the ABS come back on make the problems reappear. Does
anyone have any thoughts?
MajBach

Re: Interesting ABS problem
 

MajBach wrote:
>
> '96 Accord EXR, VTEC
>
> Hi again, My ABS is acting strangely. Recently, I noticed a peculiarity when
> coming to a stop: the ABS kicks in momentarily. To be more specific, when
> stopping with light brake pressure only, just before the car is completely
> stopped, the ABS releases the brake pressure and then re-applies it. This
> makes the car lose deceleration and then stop suddenly. IT only does this
> when using light brake pressure and at very slow speeds. However, the
> problem is significant enough to be potentially dangerous. If I am pulling
> my boat for example, I can easily misjudge where the car will halt be a foot
> or more.
> At first I thought this was related to another problem I had recently where
> one of my brake calipers came loose ( on the back of the car ); I guess I
> used to much anti-seize and didn't torque down the nuts enough. But this is
> definitely an ABS problem. I know this for certain because if I engage my
> hand-brake just enough to make the warning light come on, after about a
> minute or so, the ABS will shut off, as indicated on the dash. I know this
> to be normal. The symptoms during a stop are no longer. Releasing the hand
> brake and having the ABS come back on make the problems reappear. Does
> anyone have any thoughts?
> MajBach


==============================

Your four tires are not all the same diameter. ABS is sensing a
difference in wheel speed and applying itself. There is a TSB out there
about a similar problem . . . Sorry, lost the hard drive, now it's
gone:-(

Did you search google, or take a look at Tegger's FAQ?
www.tegger.com/hondafaq/ Look at the Accord section, and the TSB page.

'Curly'

Re: Interesting ABS problem
 

"MajBach" <majbach@sympatico.ca> wrote
> '96 Accord EXR, VTEC
>
> Hi again, My ABS is acting strangely. Recently, I noticed a peculiarity
when
> coming to a stop: the ABS kicks in momentarily. To be more specific, when
> stopping with light brake pressure only, just before the car is completely
> stopped, the ABS releases the brake pressure and then re-applies it. This
> makes the car lose deceleration and then stop suddenly. IT only does this
> when using light brake pressure and at very slow speeds. However, the
> problem is significant enough to be potentially dangerous. If I am pulling
> my boat for example, I can easily misjudge where the car will halt be a
foot
> or more.
> At first I thought this was related to another problem I had recently
where
> one of my brake calipers came loose ( on the back of the car ); I guess I
> used to much anti-seize and didn't torque down the nuts enough.

??

With some exceptions, torque specs assume no anti-seize is used. So if you
apply anti-seize where none is specified, and then torque to the "non
anti-seized specs," you're overtorquing the threads. Studies indicate by
about 30% or more easily, IIRC.

For example, see http://www.airheads.org/content/view/217/49/ :
"The rule of thumb for tightening spark plugs,,,,in fact almost any threaded
object, is to use about 30% less than dry specifications, when lubricated by
antiseize compound."

(Not that I advocate applying anything to spark plug threads!)

> But this is
> definitely an ABS problem. I know this for certain because if I engage my
> hand-brake just enough to make the warning light come on, after about a
> minute or so, the ABS will shut off, as indicated on the dash. I know this
> to be normal. The symptoms during a stop are no longer. Releasing the hand
> brake and having the ABS come back on make the problems reappear. Does
> anyone have any thoughts?

I'd be in the Chilton's manual, going through the diagnostics procedures.

I know, big help. But my Chilton's manual for 1985-1995 does have many, very
specific diagnostic procedures for stuff like this.

E.g. for 96 Civics with ABS features, see the diagnostic steps at
http://www.honda.co.uk/owner/CivicManual/index.html . Might be similar for
your Accord.

Re: Interesting ABS problem
 

>
>
> ==============================
>
> Your four tires are not all the same diameter. ABS is sensing a
> difference in wheel speed and applying itself. There is a TSB out there
> about a similar problem . . . Sorry, lost the hard drive, now it's
> gone:-(
>
> Did you search google, or take a look at Tegger's FAQ?
> www.tegger.com/hondafaq/ Look at the Accord section, and the TSB page.
>
> 'Curly'

Curly: an interesting diagnosis. I just woke up from a cat nap and thought I
had the solution myself. Perhaps one or more of the teeth on the bearing
housing that allow the computer to sense speed are broken. That's a complete
guess though. I like your idea better (cheaper fix) and it makes sense. For
the past several months, my car has exhibited an unusual wobble. It's
apparent at slow speeds by a definite deflection of the steering wheel by as
much as a half inch either direction. Oddly enough, there is no
'out-of-balance' feel to it at highway speeds. Also noticing more recently
(about the same time as the ABS problem), a bad pull to the left, like out
of alignment but again, not as noticeable at faster speeds. I've had similar
symptoms on tires with broken belts, but always a rear tire. Perhaps this
one is on the front. Fairly new tires however. I'll look into it more. Still
surprised that that is enough to fool ABS though.