How often do I need to replace rotors? NE1 have procedures?

[vroo//M]

Hi all,

My 97M3/4 currently have 62K miles on it. Recent inspection revealed that I need to replace the brake pads soon, and the rotors along with them. The mechanic stated that it has worn off and thinner than the originally specified. I'm a little confused because I never have to replace my rotors on my 94 Accord (sold) whenever I change the pads, just resurfacing.

The mechanic (Curry's Auto in No.VA) quoted me $446 for front axle and $426 for rear axle, parts and labor-This is a lot of money to spend on brake service, so time for DIY.

Can anyone suggest what rotors and pads to use, and the price too? (between Brembo, Euro floating rotors, and OEM for rotor and Pagid(?) for pads?). I don't do tracks, just street use. Can someone provide the procedure to do this? and list of tools?

Now about my mechanical prowess: I know how to change oil and flush coolant, and that's it:(

Thanks a lot in advance,
ES

[Scott Yu]

It's really not that bad, price-wise. I did OEM-sized Brembos for $69 ea (w/free shipping from Cox Imports, though ultimategarage.com has 'em for $60 ea) and Rotex Gold pads for some reasonable price, it was around 50-60/axle. I didn't get rear rotors as mine were within spec. At the same time I bought 2 litres of ATE Super Blue, and borrowed a friend's brake bleeder, and did rotors, pads, and fluid flush/bleed in 1 afternoon at a buddy's place. (thanks Scott and PT!). There are MANY writeups available, you can get started at unnoficialbmw.com and racepad.com. I looked up at least 4 different writeups on the net before I got started - it helped a lot to have 4 different viewpoints to work with.

If I would have done the rear rotors at the same time, the total price would have been less than $400 for BOTH axles. I like the Rotex pads - just a _little_ less bite than stock, but NO noise and NO dust. A welcome trade-off for me. You don't really need euro floaters, especially if you don't track it and you want to save $$.


As to your other question, you can definitely wear your rotors too thin, to the point where they might warp or crack easily. No amount of resurfacing can help you there.

good luck,

scott



Originally posted by vroo//M
Hi all,

My 97M3/4 currently have 62K miles on it. Recent inspection revealed that I need to replace the brake pads soon, and the rotors along with them. The mechanic stated that it has worn off and thinner than the originally specified. I'm a little confused because I never have to replace my rotors on my 94 Accord (sold) whenever I change the pads, just resurfacing.

The mechanic (Curry's Auto in No.VA) quoted me $446 for front axle and $426 for rear axle, parts and labor-This is a lot of money to spend on brake service, so time for DIY.

Can anyone suggest what rotors and pads to use, and the price too? (between Brembo, Euro floating rotors, and OEM for rotor and Pagid(?) for pads?). I don't do tracks, just street use. Can someone provide the procedure to do this? and list of tools?

Now about my mechanical prowess: I know how to change oil and flush coolant, and that's it:(

Thanks a lot in advance,
ES

[jww///95]

There are two ways to verify that rotors need to be changed:

First you can measure the thickness of the rotor at several different points and compare the smallest value to the minimum allowable rotor thickness. I don't have this number off the top of my head, but it is available for both the front and rear rotors.

Second, if experience symptoms of a warped rotor (shaking while braking, pedal shaking, etc) you need to check for what is know as runout. You have two forms of runout, one in the rotors and one in the wheel bearings. The vibration one may experience can be a result of a warped rotor, bad wheel bearing, or a combination of the two. You need a dial indicator to measure runout and your numbers should be less than .004". You can swap rotors to try and determine rotor vs. bearing problems, but as a unit, the runout should be less than .004" or .02mm (i believe that is the correct metric spec, but i don't feel like converting).

Sorry for the ramble, but this is how you determine (factually) that a rotor(s) need to be replaced.

[Kevlar]

I just replaced all four brake pads and front two rotors (the rear rotors need replacing too... but I ran outta money).

My car has 36,000 miles on it.

The process is faily simple, if you have a Bently manual and some spare time you can do it. I opted not to cause I didn't have anywhere to work on the car without being in direct sunlight.

[BAADDOG]

Originally posted by vroo//M
Hi all,


The mechanic (Curry's Auto in No.VA) quoted me $446 for front axle and $426 for rear axle, parts and labor-This is a lot of money to spend on brake service, so time for DIY.

Can anyone suggest what rotors and pads to use, and the price too? (between Brembo, Euro floating rotors, and OEM for rotor and Pagid(?) for pads?). I don't do tracks, just street use. Can someone provide the procedure to do this? and list of tools?

Now about my mechanical prowess: I know how to change oil and flush coolant, and that's it:(

Thanks a lot in advance,
ES

You can't do better then Curry's Auto in Norhtern VA. They are tops in the area for quality service, honest and fair pricing.

For a DIY, go to www.racepad.com for a great procedure and the required tools.

You can buy pads and BOM, rotors from racepad. David Holeman is a good Windy City Chapter guy to do business with.

Tell him Chris sent ya and good luck.