2006 Sonata rear rotor rusting and pitting

I just did my 40,000 mile maintenance and inspection and while rotating
the tires inspected the brakes. The good news is that that pads appear
to be less than half worn out. Yes, after 40,000 miles there is a lot
of material left. The bad news is that the rear rotors are rusted and
pitted pretty badly. I noticed they were noisey a few times this summer
when I didn't drive the car for a week or so as I was riding my
motorcycle so much. I was amazed though when I looked at the rotors
tonight as they are in bad shape. At this point, I'm just going to run
them until they finish off the rear pads, which looks like it may take a
while even with the pitting, but the certainly will need to be replaced
when the pads are replaced.

I've never seen a vehicle with rotors that pitted this badly other than
old vehicles at a junk yard that have sat for for YEARS. Has anyone
else had this problem with their Sonata? I wonder if anyone makes
stainless rotors for the Sonata. The stock rotors appear to be very
cheap cast iron, I'm guessing recycled iron. This reminds me of the
problem Ford had in the early 70s when they had a lot of body
rust-through problems which, IIRC, were blamed on recycled steel that
hadn't quite been recycled enough and had impurities throughout the
metal that caused rust to commence.

Matt

 

Is this not still under warranty?

Jim

 

I figured not as most brake related items are brushed off as "wear
items", but it probably is worth asking. The care is past the 36,000
mile point though so I suspect it is in just the "power train" part of
the warranty now.

Matt

 

If the car sits for just a couple of days, the rotors will show some rust,
but I don't know about the pitting, unless the castings were bad and had
porosity, which would (or should, depending on your stealership) be covered
as defective.

 

I've found that my Sonata rotors will rust in as little as 12 hours in damp
weather while my Buick rotors never show signs of rust even after a couple
of weeks sitting in the driveway inches from the lawn. . Must be a
different alloy?

 

Yes, all cars do that. My Chevy and Chryslers get a thin uniform layer
of surface rust that comes right off at the first use. The Sonata makes
a loud grinding noise for several stops if it sets more than a day or
two. The pitting is worse than anything I've seen on a car. The only
car even close was an 84 Accord I owned whose rotors rusted beyond
service in less than 60K miles. By way of contrast, the rotors on my
1994 Chevy are original and have 106K and 15 years on them.

Looks like Hyundai and Honda buy their rotors from the same source.

Matt

 

Yes, I'm seeing much the same comparing my Sonata to my Chevy truck and
Chrysler van. Something is obviously inferior about the Sonata rotors,
but I don't know what it is. I'm guessing you are correct though in
that it is a different composition or they are using recycled steel that
has impurities in it that is accelerating the rusting and pitting.
These rotors are complete trash in 40K miles and the pads aren't even
half worn out near as I can tell visually. That is simply unacceptable
to me.

Matt

 

This isn't uncommon, Matt. I see it mostly on cars that are drive
infrequently or for short trips, even though you don't seem to fall int
that category.

I, too, think it's a problem with the metal in the rotors. Rotors ar
covered for 5 years/60k miles, but the warranty pamphlet specifically say
rust is "not covered."

Can't hurt to ask the dealer, though. Many managers/advisors neve
actually read the pamphlet. You may wish to specifically ask for th
person who knew something about the "fuel tank air filter." I imagin
you'd be rather upset if someone told you it was covered, and you the
made a significant outing only do find out it wasn't

 

I have driven the Sonata infrequently a few times this summer as the
weather was good and the K1200LT was calling...

I don't think I ever went more than 6 days idle though as I drive the
Sonata to church each Sunday at a minimum. And no comments about Sunday
drivers!!

I figured as much as I've not see rust ever covered before.

Yes, it can't hurt to give them a call.

Matt

 

Wonder if it was a bad "batch". I,ve had 3 Sonata,s over 11 years, the
latest for 5 yrs, 80,000 km and no pitting whatsoever on any of them. As
you say, worth harrasing the dealers.
John

 

I don't think so. I've been seeing this for about 5 to 6 years or so