Earley Rotor Replacement

My 1998 540 i loves to go through rotors like it does the Z rated tires. Is this condition inherint in the model (rotor wear) normal? I have been thinking of upgrading my rotors to a slotted version and going to ceramic pads on the next change ( probably next spring) Any thoughts you have or suggestiuons would be appreciated. I have 17 in wheels with a fatter tire on the back. But it is the front tires that seem to have the extreme wear problem.

Originally Posted by Mr Bulldog

My 1998 540 i loves to go through rotors like it does the Z rated tires.

What does it mean to 'go through rotors'?

Do you mean they appear to "warp"? (NOTE: I use the word 'warp' in the 'traditional' sense to indicate that the driver feels vibration upon braking at speed).

Or, do you mean they appear to wear out?

If the latter, how did you measure the wear?

Yes, you've not quantified what you mean. My car has 135k on it. The front rotors were replaced prior to 58k, and are still there. I replaced the rears at about 90k. Based on my experience with a previous BMW 5-series, I would not call that excessive wear.

It may very well be your usage pattern. Do you live in a hilly part of PA? Do you have an auto trans? Both contribute heavily to brake wear. BTW, about 60-80% of the braking is done with the front brakes, so one expects them to wear out faster.

Next time, try OEM rotors and pads, no PEP Boys parts, please. Also, fancy rotors are for Bling, or the track.

As others have stated, you need to define the parameters of your problem. How many miles between rotor changes? Who determined you needed a rotor change? Is the rotor change based on rotor thickness? Or are your pads scoring the rotors? Rotor wear is a function of driving conditions and pad type. The more stops you make, the faster the rotor will wear. Harder pads (metallic) will cause faster rotor wear than softer pads. In addition, your front wheels handle the majority of your braking load, which is why they wear faster than the rears. Before you consider changing pads or rotor types, do some research. You may find out that you are unhappy with a new brake combo. Ceramic pads typically reduce dusting but sacrifice braking feel and bite. Slotted and drilled rotors contribute nothing to street performance and as edjack says, strictly bling. Don't just go buy something without understanding what you are getting into. Otherwise your probability for disappointment increases.

Thanks to all of you who responded to my statements, sorry I was not clear, let me see if I can explain what is happening; Answer After a while (after replacement) when I said go through, I mean two things, 1) The rotors do warp causing a very jerking stop almost within a week with squeal etc.. After about 15K miles the rotors are worn past the safety point, you can actually feel an edge on the outer rim of the rotor at that time. 2) It is also at about 15k miles that I have to replace the tires (Iusually give my mechanic instruction to see what he can do on lower priced tires, so I have been using z rated "FUSION" brand tires that are directional. My wider back tires are close to replacement when In have to replace the fronts , so I change all four at one time, along with 2 rotors , new pads etc, and it is only days before the noisy shaking braking problem returns.

I think the garage man orders through a local NAPA auto supply house.

btw, I noticed another poast that was questioning the winter tire set being the same tire width all around in place of the wider tire in the rear. I am waiting for a set of wheels and tires all the same width from Bavarian Auto in NH. I had to stay with the 17 inch wheel because the smaller wheels would not fit over my calipers.

By spring time I will have my current rims outfitted with a new set of tires and store the winter tires .

The V8 is notorius for eating tires. That is not a problem, that is normal.

The "warping" you experience is not warping but rather, deposits on your rotor. Rotor warping is extremely rare. A rebedding your pads will usually remove these deposits and restore smooth braking. The edge or lip you speak of on the outer edge of your rotor is normal (up to a point). Replacement of rotors is objective. Measure the rotor thickness with digital calipers. If within spec, keep them. It out of spec, replace them. I suspect your mechanic is simply playing to your fears and doing what you ask by replacing them prematurely and pocketing the labor.

Getting cheaper brake components and tires will not extend the life of these components. It will simply reduce the level of pain (cost) when you pull out your credit card. And it might even accelerate the frequency of change.

Originally Posted by Mr Bulldog

1) The rotors do warp causing a very jerking stop almost within a week with squeal etc.... After about 15K miles the rotors are worn past the safety point

Regarding 'warp', heed what Fudman said above. Make sure you understand every statement Fudman made, as it's not what you at first think (we all have to go through the rotor-warp epiphany at some point in our lives).

Regarding the worn rotors - we discussed how long rotors 'should' last in this thread:
- One user's example of a complete brake job with all torque figures, specs, measurements, fluids, decisions, tools, tricks, mistakes, suppliers, costs, etc., that it entails (1)

I've never tried Napa rotors and pads on my BMW, but i used the "Premium" (the second from the bottom of their quality hierarchy, I think) on my Ranger and was not impressed. The rotor "warp" developed within about a year. I tossed them and replaced them with the Napa Ultra Premium (top of the line) rotors. It's been a year (but a low mileage year) since then and they're fine.

For BMW, go with the OE parts. They're expensive, yes. It's worth it.

Unless you're autocrossing or driving in such a way that you're going through a lot of tires anyway, then I prefer premium brand tires - Michelin, Continental, Yokohama, Bridgestone, BFGoodrich. I've seen off-brands wear funny. I am actually considering a set of Sumitomo for my E39 in the spring. I don't read too much into the customer reviews on the tirerack website, but I like the tests that they perform. These Sumitomos rival the Yokohama for less money.

I think the basic story here is sometime it very wise to pay more for quality parts. A garage will generally not put the best quality parts unless requested or they are a specialist.

Your brakes shouldn't be juddering or showing too much wear that quickly, which suggest the parts aren't very good quality. Replacing them with the same parts gain will have the same results, spend a little extra and save in the long run.

The same is true with tires, never buy cheap tires for a car your going to keep. Normally spending a few % more on tires can get you tires that will last twice as long and give you more grip (improved safety). I put a pair of Continental DWS on the front of mine when i bought it, 20k later they still have ~6mm on them. It had Sumitomos on the rearwhen i bought it with ~4mm that lasted about 10k and got replaced with another set of DWS. They cost an extra $20 a tire over the cheapest tires, I am expecting at to get 40 to 50k out of the front and 30k+ out of the rear, I reckon the extra $20 will get me at least a extra 10k per tire.

What brake pads are you using? Sounds like you might be using a race pad which will cause rotor wear.

As mentioned before, "warped" rotors dont really happen. If they feel warped its because you have a high point (build up) of bedding in 1 or more areas on the rotor. To cure this you get a set of course pads(race pads) and do about 10 hard stops from 60ish. This will de-bed your rotors getting rid of the high spots that are causeing the "warp" feeling. Then you put street pads on and re-bed. Did this with my 540i that had a Brembo BBK. All vibrations(warped feeling) gone.

There are some very good articles on Stop Techs web site about brakeing physics and myths.

http://www.stoptech.com/technical-su...nd-other-myths

Originally Posted by Mr Bulldog

The rotors do warp causing a very jerking stop almost within a week with squeal etc..

Fudman was trying to tell you that rotors don't actually warp.

Read the one thread in red below for details.

- The main causes of vibration while highway driving (0) (1) (2) (3) (4) (5) & while highway braking (1) (2) (3) & why it's not rotor "warp" (1) & severe ABS shuddering while slow speed braking on bumps (1) & how fluid-filled thrust arm bushings crack and tear causing the BMW to vibrate at speed (0) (1) (1) (2) (3) (4) (5) (6) (7) (8) & a comprehensive TireRack vehicle vibration diagnosis chart (1) (jpg) with wheel match mounting hints (1) & how a worn drive shaft, flex disc, center bearing, or "giunti Boschi", aka giubo (it's not spelled guibo although it sounds like it is to some) can cause the vehicle to vibrate (1) (2) (3) (4) & how to repair the rear driveshaft seal by the differential (1) & how to repair the inner constant velocity (CV) half-drive shaft (1).

Originally Posted by vavet5308

The rotor "warp" developed within about a year.

In most cases, the so-called "warp" is merely due to the driver's habits when braking, particularly when braking at speed to a stop. The cure is first to rebed, and then to change braking habits.

Of course, turning the rotors and replacing rotors will also cure the problem - but - if the driver doesn't change braking habits - the "warp" will be back (in theory anyway).

Originally Posted by mbell666

Your brakes shouldn't be juddering or showing too much wear that quickly, which suggest the parts aren't very good quality

I don't think the OP actually 'showed' wear to the rotors yet (there really is only one way to do it and that is to measure them).

Also, I don't think the fact the OP has vibration upon braking is any indication of a problem other than braking habits.

Of course, I could be wrong - as I only know what's stated - but I do know these two things (which is why I asked the question in the first place).

1. People often confuse deposition-related shuddering with bad parts when, in actually, it's due to bad braking habits. Certainly I've had this type of deposition, as evidenced by it going away with a dozen bedding runs.

2. Without a bona-fide measurement, it's hard to know whether a rotor is truly worn or not. Certainly I'd never trust myself to make that decision. That's why I have a micrometer.

Originally Posted by JasonSC540ia

As mentioned before, "warped" rotors dont really happen.

Fudman and Jason are trying to tell you that rotors don't actually warp.

There is one test you can run that doesn't cost a cent. Simply find a lonely stretch of highway, warm up the brakes with a few applications - and then press hard on the brakes to go from 60 to 10 - do that a few times - and then see if the shuddering moves to a different RPM or if it diminishes.

What I like about that test is that it's (often) both a free cure and a free test all at the same time.

Thanks to all of your comments they are great and have given me some things to think about. I haven't worked on my own cars for years, (I'm OLD) lol putting that aside, I will be asking my mechanic what he is putting on my car. That may answer some of the quetions right off if he is not replacing with OEM parts. Of course in the future I will insist on OEM from him. Part of the problem is usually when things need fixing as I am sure all of you have had the same issue (lack of money when needed) at one time or another.

I will pursue the self braking test (60 to 10 a few times) to see if it helps.

As for improper braking all I can say is how I drive if you guys can pick up something I am doing wrong while braking, this old dog can learn new tricks

Normal driving, when I see a red light or know I have to stop, i take my foot off the accelerator long before the need to stop, letting the auto's enertia do some of the slowing,
I don't drive up to a stop ligh and stop 50-100 fet away, never have done that kind if braking. You could say my braking is light though it might be for a longer distance than necessary I try to not put my foot on the brake and ride it, I am in the habit of completely taking my foot off the pedal until it needs to be engaged.

I have heard some speak about rebedding the pads will anyone tell me if I can do it myself or if I have to have the garage do it.

Thanks again for all your advise and comments, I appreciate it.

Where in PA. are you? If you're close to Carlisle, I'll be happy to take a look at your car.

Two additional potential root causes may be 1) brake hoses to the calipers have collapsed not allowing the calipers to properly function. 2) calipers are hung up from corrosion

Either of these will over heat the rotors . Unless you are racing your 540 , I think you are not finding the root cause to this problem .

Btw.... My rear rotors and pads are still original at 120k .... Fronts went 90k . Obviously my 5 is set up quite differently then yours ( manual 6 ) but it is not that much different .

I'm actually in Willow Street,(just south of Lancaster) which is not a horible distance from Carlisle, I would love to just get in the car and take you up on your offer, Carlisle isn't an unreachable distance, The problem I have

is that I am in the middle of some important dental work and my wife and I are getting ready for trip and wont be back in town until the 2nd week of new year. Perhaps if your still willing we can get together after that. This problem, is not new, so I am not particularly worried being critical it would be great to have somebody look at it that knows what he is doing. We will have to find a way to get each others email or phone numbers that is not on the forum

Thank You so much for your offer Tom

Bedding your pads requires nothing more than a straight deserted stretch of road. Accelerate to 60 mph and hit the brakes hard. When you slow to 10 mph, release the brakes. Do not come to a complete stop. Deposits are formed when you hold a brake pad against a hot rotor that is not moving. Turn around and repeat the process. After five times or so, you will begin to smell your brake pads. That should be enough. Then drive without coming to a complete stop so your rotors cool down. You're done.

Originally Posted by Mr Bulldog

I will insist on OEM from him.

I think few of us actually put "OEM" pads & rotors on our bimmers; in fact, you can see what is most recommended yourself over here:
- What brake pads & rotors are most recommended for street use on the E39?

Originally Posted by Mr Bulldog

I will pursue the self braking test (60 to 10 a few times) to see if it helps.

It's actually the rebedding procedure. It's explained in detail in the links I provided and below:
- How to rebed your brakes

Originally Posted by Mr Bulldog

this old dog can learn new tricks

The way I understand it, it's all about LIFTING your foot OFF the brake pedal after you've come to a hot stop. For example, let's say you're heading south on 85 and you get off on Saratoga Avenue (folks who live in the South Bay can follow me on this) ... it's a straight shot down a quarter mile hill to a traffic light. So you have to hot stop, no matter how well you plan.

BUT ... and here's the trick.

Stop a few feet before the intersection, and then roll, baby roll. The point is to NOT hot stop and leave the pads in the same place. Lift your foot a bit. Slide that rotor to a new spot.

Lifting your foot after a stop 'prevents' uneven pad deposition.

Originally Posted by Mr Bulldog

I have heard some speak about rebedding the pads will anyone tell me if I can do it myself or if I have to have the garage do it.

It's the 60-to-10 procedure we already discussed (details in the links). You don't rebed pads as much as you rebed the rotor by depositing a really really really thin film of melted pad onto the rotor.

The theory is that prevents uneven deposition also.