2006 Sonata brakes

I hit 22,000 miles just last week on my '06 Sonata GLS V6. Today I was
driving around my campus at work getting some coffee with the window open
and heard a noise that sounded like the brake wear indicators. It only
happened on right-hand turns. I figured maybe some debris got stuck
somewhere. Not seeing anything obvious, I took off my left front wheel.
To my surprise, the inside brake shoe is actually worn down to the wear
strips. The other pad is fine, and the other side of the car is fine too
(like maybe a bit under half life). What in the hell would cause this to
happen? Anyone ever see anything like this before? The earliest appt. I
could get at the dealer was next Tuesday. The only thing I can think of is
something is wrong with the caliper.

Eric

 

Certainly sounds like it. I've had that happen (not on a Hyundai yet) when a
caliper got sticky.


Caliper should be under warranty. Pads usually are not, but under the
circumstances, they should cover them, IMO. If not, talk to the dealer.

 

I didn't think disc brakes had an inside "shoe?"

Seriously, this is typically caused by the caliper binding and not being
able to float in the mount to equalize the force on both pads.

Matt

 

Alrighty then Mr. hair splitter, I meant PAD The confusing part to me
about what you say, and what I initially thought, is that it only happens
when I am turning right. If the caliper were binding, wouldn't it bind
when I turned left too? Especially if I didn't touch the brakes.

Honestly, I am having a hard time not tackling this myself. But I know the
more I do myself the less likely they will cover ANYTHING under warranty.
I am also dying to know if the inside of the rotor is shot. I assume it
would at least have some nice grooving.

Eric

 

Hi Eric:

When one pad wears much faster than the other, it's a caliper issue. Not
necessarily a bad caliper though. More often it is the slider sticking from
rust or other crud. Take the caliper off and clean the slide surfaces well.
Make sure that when you put the new pads in that they go in freely and can
slide along the caliper. A judicious application of never-seize won't hurt
either - right where the pads slide. Look closely at how the pads fit on
the caliper. The ears on many pads fit too tightly and benefit from a touch
on a grinder.

 

Don't tell us what you meant to say Mister - we don't care what you "meant"
to say...

The bind really has nothing to do with your turns Eric. You're only hearing
the noise because of the stresses that occur when a wheel turns. The
problem remains one of a hung caliper. You're up in the wonderful
northeast, and you're susceptible to the corrosion issues we all are up
here. Clean up the caliper sliders and lube them up. Make sure you have
nice, free movement of things and put it back together.

 

Thanks, Mike. I always do clean and lube the pistons when I do a brake
job...is there any other way?? I am going to leave this to Hyundai to fix
since I am under warranty. Maybe I'll get a new set of pads at least outta
the deal.

Eric

 

Yeah Eric - there is another way. The piston don't require lube - they get
it from the brake fluid. The fixed part of the caliper and the floating
part need to move across each other freely. That's where the bind usually
occurs. Corrosion builds up and the caliper does not move properly. One
pad will remain somewhat pressed against the rotor after you let the brakes
off. That's why I suggest a good cleaning (wire brush) and some never
seize. As well, the ears on the pads are very often a tight fit in the
caliper. Make sure the caliper is clean to receive the ears of the pads and
that the pads fit a bit sloppy in them. Often, this requires grinding off
just a tad of the ear. If you don't, the pads stick in the caliper.
Floating calipers are designed to be a moving system. Anything that binds
in a floating caliper is a problem and will result in premature pad wear.
Very seldom does the piston present itself as a problem. Most times it's
the two halves of the caliper that prove to be the problem.

 

Hey Eric - sometimes the visual is worth thousands of words. The next time
you take a set of disk brakes apart, take a close look at how the caliper
works. You're a smart guy... you'll be able to look at it and figure out
how it should work. There's really nothing magical about it. Pretty much
common sense stuff.

 

Yes, Mike, I do know how the caliper works. I'm just not using the
right terminology here. Mostly from a lack of sleep and some new
medicine the old doc has me on for cholesterol. Seems to be taking a
toll on me for some reason. My son turns 5 next week and my daughter
just turned 1. I figure in about 10 years or so I might get a good
nights sleep again

Anyway, what I clean and lube are the caliper bolt sleeves. You know,
the thingies that typically have a rubber boot over them to keep some of
the crud out. I wouldn't even begin to touch the pistons themselves,
except to push them in a bit with a C-clamp and piece of wood to make
room for the new pads.

On front discs I really DO know what I am doing, even if I am not
writing it correctly. I just think Hyundai should do the work on this
one for me. And since they will give me a loaner car this time, I
really have nothing to lose.

Rear discs, OTOH, have given me a bit of a problem in the
past...especially with the type of piston that THREADS back into the
caliper. It's not brain surgery, but I have found that they are usually
corroded enough to be a real PITA.

Eric

 

It does seem odd that the left front inside pad would bind more on a
right turn than a left turn, but the disc does flex left or right with
the force applied by the tire when the car is turning so it isn't out of
the question for a difference to be noticed when turning one way vs. the
other.

Matt

 

It may be the caliper binding in the mount, not the piston binding in
the caliper. Mike was referring to lubricating the caliper where it
slides in the mount. I haven't had the brakes on my Sonata apart so I
don't know exactly how they are designed, but most disc brakes are made
to "float" in their mount.

Matt

 

To follow up to my own post, and to add to the statement I made about not
being able to wait for Hyundai, I put the car up on the lift at work today.
I have to report that my pads are fine all around. When you look at the
inside pad in poor lighting, and with my 40-year-old eyes, it can be very
deceiving.

Anyway, I removed both calipers. On the left (drivers side) caliper, there
was tons of crud inside the caliper pin shoes. Likely a result of some
flooding that has happened here a few times over the last two weeks. I
didn't drive through anything deep, but it was likely enough to cause this.

I cleaned and greased the pins on both calipers and the noise I had has
disappeared. It is really strange that the sound was so similar to the
sound that the pad wear strips make. Even the mechanic at work heard it
and told me my pads were probably gone.

Anyway, case closed for now at least. Thanks for everyones opinions and
help.

Eric