a BMT 330ci is in the workshop - they called and want to replace the
brake discs after less than 10000km. It is about 18 months old.
The car has been used occasionally within the city for short rides.
Waiting for days for the next usage, it is clear that the discs start
to corrode after some days. But can this mean that you have to replace
them that early ?!
I guess this is not a BMW-specific topic - except if they used the
Any technical hints are welcome - thanks in advance!
No. Any corrosion like this is simply rubbed off when you use the brakes.
It's I'd say near unique that the discs need changing at such a low
mileage. 30-40,000 miles is more like it. Usually at the second pad
change. The minimum thickness is stamped on the disc hub. Might be worth
getting an independent expert to measure them if you can't do this
*The longest recorded flightof a chicken is thirteen seconds *
Dave Plowman email@example.com London SW
I've done about 15k on mine and they're getting towards needing
replacement but that is over about 3 or four years. Possibly they're
worn enough that they're suggesting that you might want to replace
them while they have it instead of the "inconvenience" of takign it
back in a year's time.
No. Depends how excessive it is. Overnight rust, OK, but this is not
always the case. Even with left foot braking on a dual carriageway, if they
are that badly corroded, replacement is the only way to overcome it. You'll
also find the pads have worn funny too.
In the interest of promoting harmony, understand that there is
currently an outbreak of thread-hijacking spammers operating on
Usenet, and one of them apparently hijacked 'Ali' in this thread. Not
all news servers will propagate the hijacked thread - evidently Pete's
did and yours didn't. Pete saw the hijacked thread and didn't know
about the hijacking spammers, hence his "WTF." There's no reason to
take anything personally over this.
So, who wore out the brakes, God or the devil?
I suggest that anybody that only gets 10k kilometers on a set of rotors
would have to be riding the brakes 100% of the time the car is rolling, and
this points to the devil.
ABS unlocks the brakes. A damaged ABS would not stick the brakes shut, it
would let them be held shut by the driver in an emergency when the ABS would
be trying to let them go. If there was no brake pedal pressure to begin
with, the ABS would not be active, and would not cause excessive wear of
brake parts. The pedal pressure has to be hard enough to keep the car from
moving in order for the ABS to get into the game.
A damaged ABS would not cause excessive wear, but riding the brake pedal
Another thing that might cause "excessive" wear is a service guy that gets
paid commission. There is no way in hell a car would need new brake rotors
after only 10k kilometers (about 16k miles) of normal operation.
Sorry for the intrusion Rowland. I just replied to a post that appeared in a
group I subscribe to, I did not check the list of groups it was sent to. I
share your disdain for cross posters, but I hold no animosity toward those
that reply to a cross posted thread.
To drag this discussion (kicking and screaming, I might add) back on topic
in the depression group, being told that your brakes need significant
service after only 10K kilometers is a very depressing bit of news ...
You didn't begin the intrusion, so no major worries on that score. And
thank you for your polite and reasonable post.
I've got to have some sort of personal reason for animus, myself. This
sort of cross-posting is somewhere between amusing and irritating.
A valid point indeed. Although if like me you've got an old motorcycle,
brake maintenance every 6000 miles is entirely normal, if not `a bit
less often than I'd feared'. I've been known to wear out rear brake
pads in that distance, but not discs. What did it? Were the brakes
dragging all the time, or what? Hard to think of a pad compound that'd
wear 'em out so quickly, unless it's a mad carbon-carbon brake like they
fit to racing cars.
When I had a drum braked bike, I had to fiddle with the brakes every
weekend to keep the things working sweetly. They did work very well,
mind - but it took a lot of work ('twas a CZ with a superb twin leading
shoe front brake).
Staying on the subject of brakes: silicone grease is the magic elixer
for conventional hydraulic disc brakes, so it seems. I had terrible
trouble with my brakes `just not working quite right' - mild dragging,
and so on. Nissin sliding calipers, fitted to a Honda VFR750 (don't ask
about the VF500).
Anyway, to cut a very long tale very short: after replacing lots of bits
and fettling everything multiple times to no avail, I tracked down some
silicone grease and used it in the appropriate places, and `it's all
Because my brakes, like most motorcycle brakes, don't have a protective
boot over the pistons, I give 'em a squirt with silicone spray lubricant
every once in a while - that helps reduce the frequency with which the
brakes need cleaning.
Don't use ordinary grease or oil or WD40 or similar for that: it doesn't
do the seals any favours. And do remember to clean the disc after
spraying silicone lube around the place or you'll have a very nasty
shock when you first try to slow down.
Remove the animal for email address: firstname.lastname@example.org
Sorry - the spam got to me
A stuck caliper is a function of disc brakes themselves, not a function of
ABS. Anti-lock is not the problem in this instance.
I agree that a stuck caliper will result in excessive brake wear, but the OP
did not post the other symptoms, such as worn pads, heat, noise, etc. He
took the car for normal service, and got a call that the rotors need to be
I'm only trying to get you off of the ABS system as the fault source. The
ABS is the speed sensors, valve system, and pump. The calipers exist with or
without the presence of an ABS system. I'm stuck on ABS because you said the
the problem could be "a damaged anti-lock system." By definition, a damaged
anti lock system will cause the brakes to not release in a panic stop or
hard-braking situation, but a worn rotor that arises from a stuck caliper is
much different than a damaged anti-lock system.
You need a new mechanic. If you indeed need rotors after 10k kilometers, ABS
is not the reason. A stuck caliper might exist -- indeed, it probably
does -- but the ABS itself is not the reason for the brakes to stick shut.
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