Rune Skigelstrand

"Hairy One Kenobi" wrote in message

> Very strange that the rear pads wear faster - does the handbrake operate
on
> the same pads and, if so, it is correctly adjusted?

AFAIK the handbrake never operates on disc-brakes (only on "drum" brakes or
whatever they're called in english). If you got disc in all corners there
will be a small, separate set of brakes to serve the handbrake. If the
handbrake was operating on the hydraulic disc brakes I guess a pressure drop
in the system over time would be very critical.

Regards
Rune

GravyCat

"daytripper" <day_trippr@REMOVEyahoo.com> wrote in message
news:03dftvkd2ppvmu3m3heme7r98am92s6bem@4ax.com...
> On Wed, 10 Dec 2003 09:15:00 +0100, "Pete" <escape2music@hotmail.com>
wrote:
>
> >
> >"Iain Miller" <donot@spam.me> wrote in message
> >news:iFuBb.688$Qk.556@newsfep4-
> >
> >> My wife's 96 A4 avant does - you get this very informative kinda
grinding
> >> noise!
> >
> >LOL!!!
>
> Even funnier if he *wasn't* referring to the car

Heh

That grinding sound would be her teeth I suppose.

Definitely an indication to slow down and proceed with caution.

Robert Brown

Rune Skigelstrand wrote:

> "Hairy One Kenobi" wrote in message
>
> > Very strange that the rear pads wear faster - does the handbrake operate
> on
> > the same pads and, if so, it is correctly adjusted?
>
> AFAIK the handbrake never operates on disc-brakes (only on "drum" brakes or
> whatever they're called in english). If you got disc in all corners there
> will be a small, separate set of brakes to serve the handbrake.

Rubbish. The handbrake draws a wire connected to a lever in the side of the
(disc) brake. Pulling the wire causes the piston to move outwards. I'm assuming
we're discussing the A4 or similar (have not bothered to check the start of this
thread to see if this is the case).

Careful with that word "never". Take off a back wheel one day and have a look.

On newer Saabs and lots of other cars, the handbrake operates a variant of drum
brake, even if the wheel in question is stopped by a disc brake.

/Robert
('01 A4 Avant, '99 Saab 9-3, '83 Saab 900)

Robert Brown

Rune Skigelstrand wrote:

> My -98 A6 only has pad wear indicators on the front brakes (as these are
> supposed to wear out first I'm told).

Recheck your sources. Placement of sensors was not determined due to how often
front or rear pads wear out.

The idea with having the sensors on the fronts is that loss of braking ability
on the front axle has greater consequences than losing it on the back.

>
> If your rear pads always wear out first I'd say your rear calipers are
> stuck/partly stuck and needs to be moved up/replaced.

Not always. Many will tell you that they've worn out more rear pads than fronts,
despite having fully-functional (i.e. not binding or rusted) sliding calipers
and pistons. But yes, stuck calipers will cause dragging pads, hence wear - but
this problem is easy to detect due to the outside pad wearing more quickly than
the inside one, on a given brake.

>
> This is very common here (Norway) due to salting of roads during winter.

I agree with that one, living in Scandinavia. I have had a stuck caliper on the
rear, due to salt water seeping through the rubber bellows protecting the pin on
which the caliper slides. It was sufficient to file away the rust, grease it,
refit, then replace pads. I must have dislodged the bellows through careless use
of my water hose . . .

/Robert
(Sweden)

Hairy One Kenobi

"Robert Brown" <roxbert.brxown@trxipnet.se> wrote in message
news:3FD8B65C.E4B0BAEA@trxipnet.se...
> Rune Skigelstrand wrote:
>
> > "Hairy One Kenobi" wrote in message
> >
> > > Very strange that the rear pads wear faster - does the handbrake
operate
> > on
> > > the same pads and, if so, it is correctly adjusted?
> >
> > AFAIK the handbrake never operates on disc-brakes (only on "drum" brakes
or
> > whatever they're called in english). If you got disc in all corners
there
> > will be a small, separate set of brakes to serve the handbrake.
>
> Rubbish. The handbrake draws a wire connected to a lever in the side of
the
> (disc) brake. Pulling the wire causes the piston to move outwards. I'm
assuming
> we're discussing the A4 or similar (have not bothered to check the start
of this
> thread to see if this is the case).
>
> Careful with that word "never". Take off a back wheel one day and have a
look.
>
> On newer Saabs and lots of other cars, the handbrake operates a variant of
drum
> brake, even if the wheel in question is stopped by a disc brake.

Actually, that's very often true (hence my fudging ;o), but not always.

IIRC, the 2CV (just to take an example) used an entirely separate braking
mechanism - two additional pads on the front wheels. c1937 or so.

Implementations vary.. when I fudge an answer, I try to do it properly ;o)

H1K

Rune Skigelstrand

"Robert Brown" <roxbert.brxown@trxipnet.se> wrote in message
news:3FD8B65C.E4B0BAEA@trxipnet.se...
> Rune Skigelstrand wrote:
>
> > "Hairy One Kenobi" wrote in message
> >
> > > Very strange that the rear pads wear faster - does the handbrake
operate
> > on
> > > the same pads and, if so, it is correctly adjusted?
> >
> > AFAIK the handbrake never operates on disc-brakes (only on "drum" brakes
or
> > whatever they're called in english). If you got disc in all corners
there
> > will be a small, separate set of brakes to serve the handbrake.
>
> Rubbish. The handbrake draws a wire connected to a lever in the side of
the
> (disc) brake. Pulling the wire causes the piston to move outwards. I'm
assuming
> we're discussing the A4 or similar (have not bothered to check the start
of this
> thread to see if this is the case).
>
> Careful with that word "never". Take off a back wheel one day and have a
look.
>
> On newer Saabs and lots of other cars, the handbrake operates a variant of
drum
> brake, even if the wheel in question is stopped by a disc brake.

"AFAIK" should be careful enough, don't you think?

C.R. Krieger

"Rune Skigelstrand" <skigel@hotmail.com> wrote in message
news:gF1Cb.5415$Y06.89078@news4.e.nsc.no...
>
> AFAIK the handbrake never operates on disc-brakes (only on "drum" brakes
or
> whatever they're called in english). If you got disc in all corners there
> will be a small, separate set of brakes to serve the handbrake.

The design you're thinking of (a small mechanical drum brake at the center
of the disk) *is* used in BMWs, at least. However, the Audi design actually
*does* operate directly on the disks. It is a cable-actuated *mechanical*
system (separate from the hydraulics) that clamps the rear pads to the disks
by pushing on the pistons. Personally, I think it's kind of a stupid,
overly complex and expensive design, but that's what it is.
--
C.R. Krieger
(Been there; done that)

Mark Allread

On Fri, 12 Dec 2003 00:14:33 -0000, wrote:

> Actually, that's very often true (hence my fudging ;o), but not always.
>
> IIRC, the 2CV (just to take an example) used an entirely separate braking
> mechanism - two additional pads on the front wheels. c1937 or so.

The French don't count. Well, maybe to 3. Sometimes.

--
Mark