speaky front wheel

[Matt]

My 01 Outback has a front wheel that has been squeaky for awhile now,
but I am starting to put enough facts to make a case. I don't know much
about the hardware in that area with the exception of the tire, so any
help appreciated.

Data: 01 OB - 4cyl - 63k miles - new brakes 4 months ago, 4 wheel
alignment around the same time.

Symptoms: Right passenger wheel squeaks when rolling and only when
brakes are NOT applied. In addition, it does not squeak when I turn the
car slightly to the left. This is interesting considering the car has a
strong right hand pull, even after the alignment.

What I suspect is that there is some worn part (bearing?) that is
causing the squeak and the pull. Any ideas? I would love to have a
theory to take into the repair place.

Thanks

 

[Carl 1 Lucky Texan]

My 01 Outback has a front wheel that has been squeaky for awhile now,
but I am starting to put enough facts to make a case. I don't know much
about the hardware in that area with the exception of the tire, so any
help appreciated.

Data: 01 OB - 4cyl - 63k miles - new brakes 4 months ago, 4 wheel
alignment around the same time.

Symptoms: Right passenger wheel squeaks when rolling and only when
brakes are NOT applied. In addition, it does not squeak when I turn the
car slightly to the left. This is interesting considering the car has a
strong right hand pull, even after the alignment.

What I suspect is that there is some worn part (bearing?) that is
causing the squeak and the pull. Any ideas? I would love to have a
theory to take into the repair place.

Thanks

Is that hub noticeably hotter after driving than the others?
I'm thinking you still have a brake problem - possibly a stuck caliper.

Carl

 

[Vanguard]

My 01 Outback has a front wheel that has been squeaky for awhile
now, but I am starting to put enough facts to make a case. I don't
know much about the hardware in that area with the exception of the
tire, so any help appreciated.

Data: 01 OB - 4cyl - 63k miles - new brakes 4 months ago, 4 wheel
alignment around the same time.

Symptoms: Right passenger wheel squeaks when rolling and only when
brakes are NOT applied. In addition, it does not squeak when I turn
the car slightly to the left. This is interesting considering the
car has a strong right hand pull, even after the alignment.

What I suspect is that there is some worn part (bearing?) that is
causing the squeak and the pull. Any ideas? I would love to have a
theory to take into the repair place.

Thanks

- Pebble stuck between rotor and brake pad.
- Piston not retracting when you let off the brakes (the stuck caliper
mentioned in the other post).
- Worn pads that need to be replaced (if it squeaks only when brakes
are applied). Since they were replaced recently, did they remember
the metal backing plate or to use the brake grease?
- Worn wheel bearing (usually more of a groan than a squeak).
- Broken coil spring (if squeaks when bouncing).

Don't know how your auto shop operates but I can usually get a free
inspection from mine.

Alignment won't fix a tire that is out-of-round. I had them check
alignment and suspension but couldn't get rid of the pull until I had
the tire checked and found it was pressed off-center so replacing it
fixed the pulling problem.

 

[johninKY]

Rotate tires from front to back. If the hard pull goes away then you have
a tire problem. Take the car for a short drive. Let it coast to a stop
without using the brakes. If the RF rotor is hot to the touch then the
pads are dragging.

 

[Dmitriy]

I'm having the exact same problem... 2000 2.5RS. Hopefully we can find
a solution, but seeing how the caliper was quite rusty when I changed
my pads, I think that might be the culprit!

Here is a thread I started on RS25 today -
http://www.rs25.com/forums/showthread.php?t=52225

 

[AS]

I have found squealy brakes in the past to be caused by:

Lack of grease between the pad and shims
Pad spring shims bent out of shape thus not pressing against the pad
Poor pad quality

The fact that the noise goes away when pressing the brake pedal leads me
to believe that the caliper is working fine.

I have also found that the hub grease seals, when without proper
lubrication, can cause a pretty loud squeal.

Good luck

 

[Uncle Ben]

Matt wrote:
....

Symptoms: Right passenger wheel squeaks when rolling and only when
brakes are NOT applied. In addition, it does not squeak when I turn the
car slightly to the left.

....
This problem has been written about before in this forum. As far as I
have seen, nobody has pinpointed the solution I found when confronting
the exact same problem:

Greasing the channel in which the caliper slides solves the problem,
but only for a few weeks. This supports the theory that the caliper
does not fully open when the brake pedal is released.

Maybe someone can suggest a more permanent cure.

 

[Dmitriy]

You mean the channel in which the brake pads slide? That is kind of the
place I'm narrowing down the problem to. Maybe the shims that go into
that channel need to be replaced or something.

 

[Uncle Ben]

The brake pads are fastened to the two faces of the caliper, so yes.
When the brake pedal is pressed, the caliper faces (with the pads) are
squeezed hydraulically against the rotating brake disk.

When the brake pedal is released, the faces of the caliper (with the
pads) are supposed to back away from the disk. I don't know if there
are springs that force that, but if there are and they are weak, maybe
that would leave one of the pads rubbing lightly against the disk,
making the squeaky noise. Similarly if the caliper faces can't slide
freely, needing lubrication in the channel.

 

[AS]

There are not such springs to return the pads. The pads return due to
the flexing of the suspension components and any run-out that the brake
disk may have.

The only springs in most systems, are the shim springs that are in
charge of holding the pads firmly in their sliding groves, so there are
no vibrations that could lead to noise (squeaks), and to prevent knocks
caused by the pads moving freely in there.

When the pads/surface of the disk are not adecuate, the brakes can make
noise even if this shims are doing their job correctly.

 

[AS]

Forgot to clarify that in most systems, the pads are not fastened to the
caliper faces. There are a systems that use pads with springs that
lodge inside the caliper pistons or that have springs to hold them
against the casting of the caliper, but those, in my book, are the
exception.

 

[Edward Hayes]

The pads are pushed be the caliper piston which is sealed with an
O-Ring. The O-Ring slightly deforms and provides the force to move the
piston back a few thousands of an inch.

 

[Bob Bailin]

The pads are pushed be the caliper piston which is sealed with an
O-Ring. The O-Ring slightly deforms and provides the force to move the
piston back a few thousands of an inch.

Until you get a buildup of rust in the caliper bore under the piston boot,
which prevents the piston from sliding easily back into the caliper. This
results in the inner pad dragging against the rotor, causing squeaking,
heat buildup and premature pad wear.

You can remove this rust buildup with fine sandpaper, either by hand
or with a rotary tool. Remove the piston and piston seal (not an o-ring)
first. Use extremely fine wet-n-dry sandpaper to polish the piston surface
to get rid of any surface rust marks. Don't sand the caliper bore behind
(inside) the seal groove. When you're done, the piston should easily
slide into the bore before you reinstall the seal (if the bleeder screw is
open to allow the trapped air to escape). If you're not replacing the
seal, use a fingernail (not a metal object) to remove any rust buildup
on the seal's surfaces. If you have a rotary tool and a soft grinding disk
that fits the seal groove, you can very carefully use it to remove the
rust buildup at the bottom of the groove that may make the seal
fit tighter than it should. (A similar rust buildup occurs inside the
caliper slide bores, on the surface of the rubber boot.)

With everything cleaned and reassembled, the caliper piston slides
back into the bore with only moderate finger pressure, no c-clamp
or other tool needed.

Bob

 

[Dmitriy]

I think this may be my problem. I just reassembled both of my front
brakes (EXCEPT the calipers themselves) cleaning all the corrosion from
all brackets and lubricating all appropriate places... it's still
squeaking.

I will try to clean the caliper as much as I can... because it really
is rusty.

 

[Dmitriy]

I think this may be my problem. I just reassembled both of my front
brakes (EXCEPT the calipers themselves) cleaning all the corrosion from
all brackets and lubricating all appropriate places... it's still
squeaking.

I will try to clean the caliper as much as I can... because it really
is rusty.

 

[Kim W]

I would suspect the tyre. Change the tyre with your spare and observe.
Cheers
Grumby