Brake rotors and fan belts

giovannir

While on a service visit at the dealership for my 1999 BMW 328i (manual shifter, Sport Pkg), I was told that I should soon replace the brake rotors (together with the pads) and the fan belts. The car has 29,000 miles and is driven mostly in town, commuting. I don't consider myself an aggressive driver. I can understand the brake pads, but I am not sure about the rotors and the belts, given the relatively low milage. Is this work likely to be necessary, or is it just a way for the dealership to make more money?
Any way to tell for sure?

vidtech

sure you can.pull the wheels and take a look at the rotors and brake pads.while your checking oil,look at the belt(s).are they severly cracked?are there chuncks missing?age and heat will deteriorate the belts.your driving habits may be the result of early brake wear.

Mr_Shiftright

What you have to do here is ask the specific reason for replacing the brake rotors:

Are they:

1. warped? How did they determine this? (dial gauge, also called "run-out" guage).

2. out of spec? If so, what is the thickness measurement of the current rotors on your car versus the factory minimum?

3. Severely grooved? (show me please)

As for the belts, you can ask why also:

Are they:

1.Conspicuously cracked?
2. Shredding?
3. glazed from slipping?

So ask for measurements on the rotors or visual evidence on the belts. If the shop can't give you either, go somewhere else where they don't recommend repairs based on using a dartboard in the office.

zueslewis

service advisor reading off of the menu, too.

ksoman

A 1999 is likely to be 4 or 5 years old by now. If you were in a place like phoenix, az, just the age of the car, rather than the miles would cause the rubber thingies to show age and begin the cracking routine.

However, brakes do not just age.

Your mileage sounds alarmingly low for a 4-5 year old car. With mostly city driving, and a likely average of 400-700 miles a month, you are likely doing a lot of stopping and too little driving, so you just might have lost your brakes (though your mention of manual tranny makes that less likely).

Second opinions definitely.

ksso

giovannir

Mr. Shiftright, I like your crisp questions, that should really help me get to the bottom of this issue. I want to get away from the dealership's dart board!
As for my locale, I do live in Central Florida, which is known for hot and humid weather. This could explain the belts, but not the rotors.
I bought the car new and always pampered it: the dealership's advice does sound perplexing to me.
Thanks to all for the advice.

Mr_Shiftright

Well it could all be on the up and up. My only concern is that the dealer should tell you how they arrived at the conclusion they arrived at. If the answer is "well, it's time", that is a bit debatable at your mileage.

Of course, I'm a big fan of preventive maintenance. As Confucius say: "Journey of one thousand miles begins with broken fan belt".

swschrad

so since I vacation a hour from the nearest ford dealer, assuming you got back to the road OK from the wilderness area, I carry spare belts.

bigorange30

I have a 1990 Ford Mustang with 122K miles. I am having trouble with a shimmy when I brake. I ahve had 2 mechanics look at the rotors and tell me they were fine and did not need to be turned. I have read somewhere that it might be the calipers. Is this true and how do I check that out? What actually might be happening with the calipers? I am on the 4th set of pads on the front disks and this didn't start until about 5K miles ago.

If I were to replace the rotors, who has the best ones? I thought maybe cross drilled and slotted would be best but don't know what brand is best.

Mr_Shiftright

I think cross drilled are a waste of money but any rotor you can buy that is thicker and has a better heat dispersion design would be good. Calipers could be sticking or dragging but it's not an easy thing to diagnose. A brake rotor shimmy would be related to the car's rolling speed, that is, you can feel the shimmy in the brake pedal and the shimmy will slow down as the car slows down. A quick violent shimmy that is not felt through the brake pedal but only through the steering wheel is probably front end related and the sign of something dangerous.

yo4

My 323si has 65K and I had mine serviced about 1 month ago. I replaced the belts, they're cheap, they do deteriorate and they can cause severe damage to your vehicle or leave you stranded.

They also told me that the pads AND rotors need to be replaced. About 2 weeks later the brake light did come on so they were right about that. FWIW, there's no need to replace the pads early and you have awhile even after the brake light comes on.

I'm going to shop around on the brake job. I did ask the questions and was told that the rotors were undersized due to wear. I sincerely doubt that. The rep is probably recommending this because it is "non-optimal" for performance and BMW could be liable otherwise (that is just my personal opinion). I had this happen to me once before (on another vehicle) and went somewhere else, had the pads replaced and drove for another 50K with no issues. I plan to do the same here. It really can't hurt much. Replacing the pads should be less than $150 so I guess the worst case scenario is that new pads won't work well and end up warping the rotors (due to being undersized). What's the fix? New pads and rotors. Seems like the risk of losing $150 (i think it will be less) is worth avoiding just getting everything done for around $600.

I'm looking for a qualified service center now. I don't want to get this done at Pep Boys or something foolish like that. I'm also looking for pad recommendations. I have the 323si so any advice would be great!

andre1969

to actually warn you when your rotors/pads are going bad? The only time I've ever seen a brake warning light come on is if you lose fluid pressure or if you forget and leave the parking brake on.

I know pads normally have those little wear indicators on them that let out a horrendous shriek when you're getting close, although I've also learned not to get too dependent on those!

yo4

The light comes on when the pad wears far enough to release a pin. I don't know this first hand, but was told that there is a sensor to detect when that pin releases. The brake light blinks then flashes if there are more urgent problems.

alcan

If it's similar to Mercedes, there's a sensor with 2 non-connected wires embedded in each set of pads. When the friction material wears down to where both wires are uncovered and touching the rotor, the rotor completes the circuit between them and provides the ground path for the light.

andre1969

Does it make the cost of the pads very expensive, though? If nothing else though, it beats the hell out of having to actually pull of a wheel every so often to check on how much life your pads have left!

alcan

There isn't that much to the sensors, and they're available seperately. I've modified aftermarket pads with a drill press to accept the sensors (they just pull out of the old pads). Works like a champion for 1/2 the price of OEM pads.