Rotor Replacement Challenge

Usually, replacing the brake pads and rotors an any late 90s BMW 3 or 5 series is pretty easy.

1. Remove the wheel - 5 bolts
2. Remove a spring clip
3. Remove 2 7mm bolts holding the caliper
4. Remove the 6mm rotor retention screw.

That's about it
Unless the rotor retention screw won't come out.

These screws get stuck more often than anyone likes. Here are some links to some videos on the topic:
How to Remove a Stripped Rotor Locator Bolt
Drilling Out Stripped Brake Rotor Screws
Removing Brake Rotor Screws That Won't Come Out

While replacing the front pads and rotors on the 98 M Roadster I found a rotor retention screw that had been badly mauled. My best guess is that someone had trouble removing the screw and then re-installed it for me to learn from - how nice.

I didn't remove the screw. Here's what I did:

You may wonder why I didn't use an "easy out". My experience with using an easy out has been all bad. I broke an easy out in a drilled out bolt and found myself in worse shape than when I started.

It does bother me that I left that screw in the hub, with a little work I'll get over it.

Cool Carbon Brake Pads

Yes, they really are good. There is a dramatic difference in braking between these and the metallic pads I was using before.
The metalic pads had a grinding feel to them, these are smooth. The metalic pads took more foot preasure to engage than the Cool Carbon pads.

the box came with four pads, the instructions and a sticker.
The bedding instructions that came with the pads were crazy - at least they seemed crazy to me.

From the instructions

• Perform a series of 10 to 12 partial stops from 70 to 20 mph with the first 3 under moderat braking, increasing to 75% to 90% of full braking during the series of stops"
• Performance should increase somewhat during this process and fall off toward the end of this cycle.
• Do not come to a complete stop during this cycle, if at all possible, as this may interrupt the material transfer proces to the rotor surface; Note: material transfer process will take longer with new rotors.

There is more but you get the idea.
So what is crazy about this?

• Finding a road where you can do 10 to 12 accellerate to 70 and then brake down to 20 mph is not easy
• The instructions go on to recommend "Repeat the above sequence, including the cooling section" so I'm suppose to go through the cycle twice.
• When you are trying to find a stretch of highway deserted enough to do 10 to 12 runs to 70, brake to 20 and then cool down it's easy to lose count - was that 8 or 9?

I should have checked the website they have new instructions that indicate a long term break in method along with a modified fast break in.

All that aside, I like them.

How Does an M Roadster Sound?

I think it sounds better at idle than at high RPM
About half way through I experiment with picture in a picture mode on my video editor

The Brake Rotor Controversy

Plain, slotted or cross drilled?
In 1998 BMW M models came with plain rotors.
In 2010 the M3 comes with drilled rotors.

Do slots or holes or both actually help?
After much searching I didn't find anything I'd call authoritative on the subject. I chose to go stock solid rotors. The information from brembo at tirerack.com helped make my decision. (the brembo logo uses a lower case "b"). I ordered stock rotors and ceramic pads - rotor and pad replacement video to follow.

The bottom line is that in their advertising brembo appears to emphasize the appearance aspect of the slots or holes rather than the performance aspect. They indicate that drilled rotors should not be used with racing brake pads at all.

Here is the actual verbiage -

brembo Sport Slotted Rotors
On the "Product Description" tab is the following disclaimer:

"Brembo Sport slotted brake rotors are designed to meet the challenges of high performance street driving while adding an authentic, race-ready look.

NOTE: Brembo Sport slotted brake rotors can be used in conjunction with race compound brake pads on the track for drivers’ schools and lapping days.

IMPORTANT REMINDER: Slotted, drilled or dimpled rotors offered as OEM replacements should not be considered appropriate for high-speed track use.

While grooved, drilled and slotted rotors offer an enhanced appearance and add some resistance to the boundary layer of gasses that can build up between the pad and rotor, they are not designed to withstand the extreme temperatures that are produced on the racetrack. If they are used on the track, it is very important that the rotors be carefully inspected and should not be driven on if even minor signs of deterioration are seen. Note, too, that if any products are used on the track they are not warrantable"

brembo Sport Drilled Rotors 
On the "Product Description" tab is a similar but slightly different disclaimer:

"NOTE: Brembo Sport drilled brake rotors are not recommended by The Tire Rack for track use or intended to be used in conjunction with race compound brake pads on the street. For severe duty brake demands see Brembo Sport slotted brake rotors.

 IMPORTANT REMINDER: Slotted, drilled or dimpled rotors offered as OEM replacements should not be considered appropriate for high-speed track use.

While grooved, drilled and slotted rotors offer an enhanced appearance and add some resistance to the boundary layer of gasses that can build up between the pad and rotor, they are not designed to withstand the extreme temperatures that are produced on the racetrack. If they are used on the track, it is very important that the rotors be carefully inspected and should not be driven on if even minor signs of deterioration are seen. Note, too, that if any products are used on the track they are not warrantable."

brembo Replacement Rotors have no disclaimer. Maybe it's because they don't think people will track plain rotors and so they don't need a warning.

brembo has it's own website. The advertising there indicates benifits in water, to dissipate heat and eliminate brake dust and gases.

Convertible Rear Window Cover

BMW didn't start putting glass windows on the rear of a convertible until the E46 in 2000.
So, if you have a BMW convertible 1999 or older you have a plastic rear window.

The plastic scratches during normal use. Convertible tops wear during normal use.
Having a cover over the window when putting the top down helps reduce wear.

You can buy a cover or make one yourself like I did.

A Short Lesson On Tire Safety

This 52 second video covers two basics of tire safety

1. Tread wear
2. Dry rot

I've had enough experience with worn tires in wet weather to testify as an expert witness on the importance of having enough tread depth to channel water out from under a tire to attain safe traction.

I use to believe that tire dry rot was something invented by the tire sales people. Rubber may crack over time but the tire is held together with steel and fiber strips - right?
My wife experienced the reality of a dry rotted tire flying apart while going down the highway. No one was injured, the vehicle was damaged, and the passenger was freaked out. I take dry rot seriously.

Some articles indicate that dry rot is only a problem if the cords inside the tire are showing. I know this is not true. The tire that flew apart on the highway looked fine except for the tell tale cracked rubber.

Spring is Here

And top down weather has come once again.

I have some plans for this spring.

• replace warped front rotors and brake pads (maybe paint the calipers)
• replace floor mats
• Make a rear window cover using 8 pound pull rare earth magnets

In the meantime it's great just having the top down.

E39 Wipers - BMW 5 Series 1995 - 2003

My 2002 530 needs wipers - bad.
Two ways to fix this problem,

1. Replace just the blade - I was never happy with the performance of the replacement blade.
2. Replace the whole wiper - I have been happy with the performance of the new wipers but they were a hassle to get.

Normal wipers won't work on the E39, they are way too cool for that.

If you want to replace the whole wiper auto parts places around here don't stock the part. I ordered from Bavarian Auto in the past (part number 61 61 9 070 579). The wipers cost $57 plus shipping and take a few days to get here.

I found out that the NAPA part number is 3397001539 and my local O'Reilly can get them in just two days for $55

If I had shopped around a little harder I might have found them in stock somewhere close.

Hitting 100,000k

The M Roadster rolled over 100k miles a few weeks ago. Once upon a time that was an amazingly huge number of miles for a car. I see it as mid-life for most cars made in the last 20 years, especially this one.

Last week I was driving to work, I was on the highway and felt a vibration in the front end. It felt like I had lost a wheel weight and one of the wheels was out of balance. It wasn't terribly bad so I kept driving.
Turned out the vibration was a sticky brake caliper draggin on the rotor.
Normally this is the sort of thing I'd fix but I was no where near home and I felt lazy so I let the shop fix it. Add $288 for parts and labor to my maintenance tally.
I suspect front brake rotors are in my near future. The mechanic said it was obvious that it got pretty hot.