Binding brake pads on A4
 

All,

This one for those of you with own experience of brake pad replacement.

I have just replaced front pads and disks on my 2001 (B5) A4 Avant. I am
now getting slight overheating on the right side, probably due to the
pads binding on the mounting frame and not leaving the disk when brake
pedal is released.

When I installed the pads, I noticed that the "hooks" on the pads were
very tight going over the frame. Had to tap them into place, methinks
this is not such a good sign ;-) My impression is that there should be a
bit of play.

Should I consider filing the insides of the pad hooks slightly, so that
the fit is slightly looser? If I were to do this, the overheating will
stop, but I wonder if maybe this would cause the pads to start rattling
around a bit. Would they?

I am unfamiliar with the peculiarities of brakes on the Audi, though I
have rebuilt/reconditioned tons of brake calipers on old Saabs.

Tnx for your input /Robert

Re: Binding brake pads on A4
 

There should not be any play. You should use a little caliper grease to
keep them from binding. Unless you had to "hammer" rather than "tap"
them on, I would guess your caliper needs to be rebuilt or replaced.

Robert Brown wrote:
> All,
>
> This one for those of you with own experience of brake pad replacement.
>
> I have just replaced front pads and disks on my 2001 (B5) A4 Avant. I am
> now getting slight overheating on the right side, probably due to the
> pads binding on the mounting frame and not leaving the disk when brake
> pedal is released.
>
> When I installed the pads, I noticed that the "hooks" on the pads were
> very tight going over the frame. Had to tap them into place, methinks
> this is not such a good sign ;-) My impression is that there should be a
> bit of play.
>
> Should I consider filing the insides of the pad hooks slightly, so that
> the fit is slightly looser? If I were to do this, the overheating will
> stop, but I wonder if maybe this would cause the pads to start rattling
> around a bit. Would they?
>
> I am unfamiliar with the peculiarities of brakes on the Audi, though I
> have rebuilt/reconditioned tons of brake calipers on old Saabs.
>
> Tnx for your input /Robert
>

Re: Binding brake pads on A4
 

Jim wrote:

> There should not be any play. You should use a little caliper grease to
> keep them from binding. Unless you had to "hammer" rather than "tap"
> them on, I would guess your caliper needs to be rebuilt or replaced.
>

Thanks for your tip. No, the caliper is fine. Brake piston returns smoothly
and easily, piston seal is fine, guide pins and holes sliding freely in
relation to each other, without play.

But you got me thinking along the lines of "no play" vs. "too snug", for the
brake pads on their mounting frames. In my case, even with the copper grease,
they were "too snug". This morning, a couple of strokes of the file, plus more
copper grease, got the pads moving laterally, freely, and without introducing
play.

/Robert

Re: Binding brake pads on A4
 

> I have just replaced front pads and disks on my 2001 (B5) A4 Avant. I am
> now getting slight overheating on the right side, probably due to the
> pads binding on the mounting frame and not leaving the disk when brake
> pedal is released.

Now my question is how do you know it's only the right side that's
overheating? Do you keep dipping your index finger through the rim while
driving? :)

Re: Binding brake pads on A4
 

JP Roberts wrote:

> > I have just replaced front pads and disks on my 2001 (B5) A4 Avant. I am
> > now getting slight overheating on the right side, probably due to the
> > pads binding on the mounting frame and not leaving the disk when brake
> > pedal is released.
>
> Now my question is how do you know it's only the right side that's
> overheating?

Because the left side is much cooler.

> Do you keep dipping your index finger through the rim while
> driving? :)

Something like that. First I drive around with minimal use of brakes (use
clutch or engine braking to stop the car, preferably on an uphill section if I
can find one). Idea is that no brake pedal has been used in the process. In
fact, to check front brake drag, you can stop the car using the handbrake,
which activates the rear wheels of course.

Disks should not be hot to the touch; right and left ones should be of similar
temperature. And yes, I poke my fingers through the rim to check them.
Carefully. I don't know of any other way, do you?

Then I repeat the test, after driving around with lots of brake pedal. This
time it suffices to hold the hand close to the disk. It's just a matter of
comparing the heat radiating from each side.

Removing both wheels and rotating the disks by hand will also give a good
indication of where the problem is.

/Robert