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      02-06-2018, 06:04 AM   #1
Daggers
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F3x brake rotor/disc & pad replacement guide

I've done this a lot, but figured I'd document this for those that haven't changed their brakes before. I couldn't see a guide already. This applies to any car fitted with brembo 4 pot factory calipers (inc M sport/M Performance etc).

BMW quote 2 hours for this, which at £120 an hour at my local dealer equates to a LOT of money, plus the hassle of driving there at a time to suit them. Do it yourself - if you've not done it before you'll be surprised how easy it is, and it'll build your confidence with general maintenance.

Standard disclaimer - if you die horribly in a fireball or your wheels come off, or you hurt yourself because you dropped a brake rotor on your foot, etc etc, I’m not responsible. Notwithstanding that...



Difficulty rating:
2/10

Time required:
45mins - 1.5 hours depending on experience/confidence/how many cups of tea you stop for.

Tools Required:
Axle stands / jack.
1/2" Ratchet.
10mm & 17mm sockets.
HW6 socket (or 6mm allen key).
Torque wrench.
Breaker bar (useful, not essential).
1/2" Impact driver (again, useful not essential).
Drift/pin/modified screwdriver - for driving out the pad retaining pins.
Hammer.
Medium sized pry bay.
Small towels/tissues.
Small wire brush.
Brake cleaner.
Copper grease (copper slip).
Small brush (for applying copper grease).
Paper towels.
Small syringe.

Parts Required:
F30 brake discs/rotors (here I'm using M Performance 370mm discs, but the same process applies regardless of your disc size - just get the right discs for your car)
F30 Brake pads (all F3x brembo pads are the same - here I'm using F80 M3 EBC Yellow Stuff pads which are a good compromise for fast road with occasional Nurburgring use and are a favourite of mine)

The Process:

How to replace your brake discs/rotors and pads.
Firstly, open the bonnet and remove the trim covering the brake servo. Photos show a RHD car but the same applies for LHD car. The trim is held in by three 10mm bolts that simply need a quarter turn to unlock. Once the trim is removed, undo the brake fluid cap - this is so when you push the calipers pots back into the caliper later, it’s easier for the fluid to move back through the brake lines.





Wrap the reservoir in tissue/rag etc - again, for later. If fluid spills out as the pots retract in the caliper, you’d rather it went on a rag than down your engine bay



Next, get the car up in the air. If you have a ramp at home, ideal, and will make the process easier. Failing that, get it nice and high on axle stands.

Take the wheels off, and put to one side.



Removing the pads.
Next, remove the pads. Turn the wheels to the opposite side to the side you’re working on, so the rear of the caliper is most exposed. You’ll need a little punch (or in my case, a modified screwdriver with a ground down head) to drive the pad retaining pins out. Drive them through from the outside face of the caliper just enough to allow you to use pliers to pull them the rest of the way out. They're in there quite tight by design - you'll need to tap your drift with a hammer.



Now the pads are exposed, they’ll still be tight in the caliper against the disc. You’ll need to gently lever the disc slightly against the inside of the caliper (between the pots inside the caliper) to make the gap a mm or so wider so pad removal is easier. You should now be able to remove the pads by hand.



If you’re working on the side with the pad wear sensor (left hand side on RHD models, don’t know if it’s the same on LHD cars but presume so) then you’ll see the wire from the pad. Remove the wire from its little metal clip on the strut (pulls out easily enough with a bit of force) to give you more room to work. Then carefully remove the sensor from the pad being careful to not lose the tiny spring holding the sensor in the pad. It just wiggles out - don't be tempted to use pliers and risk damaging the sensor. See photos. Once it's out, clean it with paper towels and brake cleaner carefully.











Removing the caliper.
Now the pads are removed, we need to remove the brake caliper itself. This is simply held in by two 17mm bolts at the rear. These are tight, so you’ll need a breaker bar or bloody strong arms and a ratchet. Have some cable ties handy so when the 2nd bolt is removed, you can suspend the caliper from the spring - don’t let the caliper hang! The disc is already removed in this photo, but you can see the caliper is simply cable tied up (to the suspension spring).





Removing the disc/rotor.
This is simply held in by the single small 6mm retaining bolt (allen key). Once the bolt is removed, the disc is simply held on by friction. Give the disc a few taps on the hub area with a hammer, and the disc should simply 'fall off' into your awaiting hand. Photo shows the HW6 bit on the new disc (I forgot to photo it on an old disc still on the car, but it's the same obviously!)





Cleaning.
It’s really important to clean the face of the now exposed hub. I mean REALLY important. Wire brush it, scrub it, remove all traces of dirt or rust that’s there. 99% of brake judder is caused by either pad material build up on the disc, or from hub runout, which can easily be caused by grit etc between the hub and disc. You want it this clean:



Now is the time to clean the inside of the brake caliper too - brake dust builds up inside and can cause binding and squealing. Use a small metal brush on the top and bottom of the inside only - don’t try to clean the pots or the surfaces around them as you risk damaging the dust shields. Also clean the spring pad retainer and the pins to remove as much built up brake dust and crud as possible.





Now clean the disc both sides with brake cleaner and put clean gloves on if you can. It’s important to keep the disc as clean as possible from now on - you certainly don't want to contaminate them with grime and copper grease (in the next step)

Fitting the new rotor/disc.
Offer the new disc up to the hub, and align the holes so the retaining grub bolt hole is over it’s corresponding hole in the hub. Refit the bolt and tight to 16Nm using a torque wrench.

Refit the caliper - simply the reversal of removal. Tighten the caliper bolts to 110Nm using your torque wrench. It's easier to put the lower bolt in the caliper first (looking down from the top) so you can line up the bolt and hole.



Fitting the new brake pads.
Now prep the brake pads ready for installation. You want to grease the REAR of the pads with copper grease/copper slip. A thin layer is all that's required, don't slather it on. Carefully grease the small edge of the pad where it will contact the caliper. Take care to not get ANY copper grease on the pad friction material - especially when applying it to the thin side section of the pad. See photo.





You'll need to push the caliper pots back into the caliper - there's a 'proper' tool for this (called a caliper rewind tool), but given how much it costs, and how easy it is to push them back in by hand if you're careful, that's the way to go in my opinion. Using your pry bar, push each pot into the caliper carefully - you'll notice the alternate pot on the same side will likely start to push out as the fluid transfers in the caliper. If you alternate between them, and use your fingers to hold the other pot down, you can slowly work both back so they are flush with the inside of the caliper. Do the other side of the caliper after the first side pad is in for ease.

This is why we unscrewed the brake fluid reservoir earlier - the fluid from the brake calipers and lines needs to go somewhere - back into the reservoir.

Once the pots are flush inside the caliper, insert the prepped brake pad. On the side with the brake pad wear sensor, insert the sensor first obviously, remembering to clip the cable back in it's metal clip on the strut. The little dimple on the sensor should be facing the disc (IE, on the side where there's friction material. See photo.



Loosely insert the top pad retaining pin (inserting from the rear of the caliper), and slip the spring under it. Then bend the spring down, and insert the lower pin. The second photo below shows the back of the caliper with the pins inserted but not knocked in yet.





You should end up with this:




Make sure you knock the pad retaining pins all the way back into the caliper so they're almost flush with the rear of the caliper - use a hammer but be careful not to damage the paint on your calipers - it's not visible back there but be careful anyway.

Final steps.
Now we've assembled all parts, give everything a clean with liberal amounts of brake cleaner and paper towels. You really can't overdo this part! Your brakes work hard for you and you should treat them well . It's also a chance to get into crevices you can't access with the wheel on for cleaning but ARE visible - so go to town.



Lastly, we may have excess fluid in the reservoir from where we pushed the pots back into the caliper. Refit the wheels, and lower the car. Torque the wheel bolts to your factory spec (140Nm in my case).



If your pads were really worn, and your brake fluid had been topped up since the last pad change, it's possible some of the fluid might have spilled out from the reservoir. Good job we put those towels/tissues down

If it hasn't, even better. Simply use a small syringe to remove the excess fluid and discard.





Completed!
Stand back and admire the fact you just saved several hundred dollars/pounds in labour.



The first time you get in the car, pump the brake pedal a few times until it's hard. It will likely press almost to the floor on the first press. Don't be alarmed.

Finally, bed the new discs and pads in. The bedding in process for pads can range from pad to pad - seek the advice of the manufacturer. I generally use the EBC guidelines:

https://ebcbrakes.com/articles/bedding-in/

You'll see on the next photo I've only done around 5 miles, so the pad hasn't yet made contact with the disc across the full width of the disc. This will come with time/miles.



Hope that helps save you guys some money!

Last edited by Daggers; 02-07-2018 at 06:59 AM.
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      02-10-2018, 02:02 AM   #2
JDuffy14
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Quote:
Originally Posted by Daggers View Post
I've done this a lot, but figured I'd document this for those that haven't changed their brakes before. I couldn't see a guide already. This applies to any car fitted with brembo 4 pot factory calipers (inc M sport/M Performance etc).

BMW quote 2 hours for this, which at £120 an hour at my local dealer equates to a LOT of money, plus the hassle of driving there at a time to suit them. Do it yourself - if you've not done it before you'll be surprised how easy it is, and it'll build your confidence with general maintenance.

Standard disclaimer - if you die horribly in a fireball or your wheels come off, or you hurt yourself because you dropped a brake rotor on your foot, etc etc, Iím not responsible. Notwithstanding that...




Difficulty rating:
2/10

Time required:
45mins - 1.5 hours depending on experience/confidence/how many cups of tea you stop for.

Tools Required:
Axle stands / jack.
1/2" Ratchet.
10mm & 17mm sockets.
HW6 socket (or 6mm allen key).
Torque wrench.
Breaker bar (useful, not essential).
1/2" Impact driver (again, useful not essential).
Drift/pin/modified screwdriver - for driving out the pad retaining pins.
Hammer.
Medium sized pry bay.
Small towels/tissues.
Small wire brush.
Brake cleaner.
Copper grease (copper slip).
Small brush (for applying copper grease).
Paper towels.
Small syringe.

Parts Required:
F30 brake discs/rotors (here I'm using M Performance 370mm discs, but the same process applies regardless of your disc size - just get the right discs for your car)
F30 Brake pads (all F3x brembo pads are the same - here I'm using F80 M3 EBC Yellow Stuff pads which are a good compromise for fast road with occasional Nurburgring use and are a favourite of mine)

The Process:

How to replace your brake discs/rotors and pads.
Firstly, open the bonnet and remove the trim covering the brake servo. Photos show a RHD car but the same applies for LHD car. The trim is held in by three 10mm bolts that simply need a quarter turn to unlock. Once the trim is removed, undo the brake fluid cap - this is so when you push the calipers pots back into the caliper later, itís easier for the fluid to move back through the brake lines.





Wrap the reservoir in tissue/rag etc - again, for later. If fluid spills out as the pots retract in the caliper, youíd rather it went on a rag than down your engine bay



Next, get the car up in the air. If you have a ramp at home, ideal, and will make the process easier. Failing that, get it nice and high on axle stands.

Take the wheels off, and put to one side.



Removing the pads.
Next, remove the pads. Turn the wheels to the opposite side to the side youíre working on, so the rear of the caliper is most exposed. Youíll need a little punch (or in my case, a modified screwdriver with a ground down head) to drive the pad retaining pins out. Drive them through from the outside face of the caliper just enough to allow you to use pliers to pull them the rest of the way out. They're in there quite tight by design - you'll need to tap your drift with a hammer.



Now the pads are exposed, theyíll still be tight in the caliper against the disc. Youíll need to gently lever the disc slightly against the inside of the caliper (between the pots inside the caliper) to make the gap a mm or so wider so pad removal is easier. You should now be able to remove the pads by hand.



If youíre working on the side with the pad wear sensor (left hand side on RHD models, donít know if itís the same on LHD cars but presume so) then youíll see the wire from the pad. Remove the wire from its little metal clip on the strut (pulls out easily enough with a bit of force) to give you more room to work. Then carefully remove the sensor from the pad being careful to not lose the tiny spring holding the sensor in the pad. It just wiggles out - don't be tempted to use pliers and risk damaging the sensor. See photos. Once it's out, clean it with paper towels and brake cleaner carefully.











Removing the caliper.
Now the pads are removed, we need to remove the brake caliper itself. This is simply held in by two 17mm bolts at the rear. These are tight, so youíll need a breaker bar or bloody strong arms and a ratchet. Have some cable ties handy so when the 2nd bolt is removed, you can suspend the caliper from the spring - donít let the caliper hang! The disc is already removed in this photo, but you can see the caliper is simply cable tied up (to the suspension spring).





Removing the disc/rotor.
This is simply held in by the single small 6mm retaining bolt (allen key). Once the bolt is removed, the disc is simply held on by friction. Give the disc a few taps on the hub area with a hammer, and the disc should simply 'fall off' into your awaiting hand. Photo shows the HW6 bit on the new disc (I forgot to photo it on an old disc still on the car, but it's the same obviously!)





Cleaning.
Itís really important to clean the face of the now exposed hub. I mean REALLY important. Wire brush it, scrub it, remove all traces of dirt or rust thatís there. 99% of brake judder is caused by either pad material build up on the disc, or from hub runout, which can easily be caused by grit etc between the hub and disc. You want it this clean:



Now is the time to clean the inside of the brake caliper too - brake dust builds up inside and can cause binding and squealing. Use a small metal brush on the top and bottom of the inside only - donít try to clean the pots or the surfaces around them as you risk damaging the dust shields. Also clean the spring pad retainer and the pins to remove as much built up brake dust and crud as possible.





Now clean the disc both sides with brake cleaner and put clean gloves on if you can. Itís important to keep the disc as clean as possible from now on - you certainly don't want to contaminate them with grime and copper grease (in the next step)

Fitting the new rotor/disc.
Offer the new disc up to the hub, and align the holes so the retaining grub bolt hole is over itís corresponding hole in the hub. Refit the bolt and tight to 16Nm using a torque wrench.

Refit the caliper - simply the reversal of removal. Tighten the caliper bolts to 110Nm using your torque wrench. It's easier to put the lower bolt in the caliper first (looking down from the top) so you can line up the bolt and hole.



Fitting the new brake pads.
Now prep the brake pads ready for installation. You want to grease the REAR of the pads with copper grease/copper slip. A thin layer is all that's required, don't slather it on. Carefully grease the small edge of the pad where it will contact the caliper. Take care to not get ANY copper grease on the pad friction material - especially when applying it to the thin side section of the pad. See photo.





You'll need to push the caliper pots back into the caliper - there's a 'proper' tool for this (called a caliper rewind tool), but given how much it costs, and how easy it is to push them back in by hand if you're careful, that's the way to go in my opinion. Using your pry bar, push each pot into the caliper carefully - you'll notice the alternate pot on the same side will likely start to push out as the fluid transfers in the caliper. If you alternate between them, and use your fingers to hold the other pot down, you can slowly work both back so they are flush with the inside of the caliper. Do the other side of the caliper after the first side pad is in for ease.

This is why we unscrewed the brake fluid reservoir earlier - the fluid from the brake calipers and lines needs to go somewhere - back into the reservoir.

Once the pots are flush inside the caliper, insert the prepped brake pad. On the side with the brake pad wear sensor, insert the sensor first obviously, remembering to clip the cable back in it's metal clip on the strut. The little dimple on the sensor should be facing the disc (IE, on the side where there's friction material. See photo.



Loosely insert the top pad retaining pin (inserting from the rear of the caliper), and slip the spring under it. Then bend the spring down, and insert the lower pin. The second photo below shows the back of the caliper with the pins inserted but not knocked in yet.





You should end up with this:




Make sure you knock the pad retaining pins all the way back into the caliper so they're almost flush with the rear of the caliper - use a hammer but be careful not to damage the paint on your calipers - it's not visible back there but be careful anyway.

Final steps.
Now we've assembled all parts, give everything a clean with liberal amounts of brake cleaner and paper towels. You really can't overdo this part! Your brakes work hard for you and you should treat them well . It's also a chance to get into crevices you can't access with the wheel on for cleaning but ARE visible - so go to town.



Lastly, we may have excess fluid in the reservoir from where we pushed the pots back into the caliper. Refit the wheels, and lower the car. Torque the wheel bolts to your factory spec (140Nm in my case).



If your pads were really worn, and your brake fluid had been topped up since the last pad change, it's possible some of the fluid might have spilled out from the reservoir. Good job we put those towels/tissues down

If it hasn't, even better. Simply use a small syringe to remove the excess fluid and discard.





Completed!
Stand back and admire the fact you just saved several hundred dollars/pounds in labour.



The first time you get in the car, pump the brake pedal a few times until it's hard. It will likely press almost to the floor on the first press. Don't be alarmed.

Finally, bed the new discs and pads in. The bedding in process for pads can range from pad to pad - seek the advice of the manufacturer. I generally use the EBC guidelines:

https://ebcbrakes.com/articles/bedding-in/

You'll see on the next photo I've only done around 5 miles, so the pad hasn't yet made contact with the disc across the full width of the disc. This will come with time/miles.



Hope that helps save you guys some money!
This is super helpful! just a few questions -
Does the same basic procedure apply for the rear?
How many sensors are there and where are they located (ill probably replace them when i do this)
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      02-10-2018, 03:41 AM   #3
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There are 2 sensors one on the front drivers side and one on the rear passenger side.

Very nice write up by the way! I just did this last month for the first time took an hour just searching and watching youtube videos lol.
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      02-11-2018, 10:46 AM   #4
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Nice write up. Did you notice much diff in the performance of the rotors? My fronts need doing and I had a look at maybe replacing them with the performance rotors just cause they look better 😀

Oh why the hell would you quote the original post to reply?
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      02-12-2018, 07:56 PM   #5
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My Zimmermann discs are currently suspect of some horrid noise. I feel the garage I used messed up during installation.

https://streamable.com/hr3ph

At first the brake shield was suspect but I've leveraged that away with full clearance, so now I'm thinking of refitting the disc. Last time I attempted (before getting the garage to do it for me) I couldn't shift the two bolts holding the caliper in.. what tool did you use? My breaker bar is around 2 1/2 ft long so it won't really clear the wheel arch
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      02-12-2018, 08:14 PM   #6
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Great write up!
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      02-12-2018, 08:56 PM   #7
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One of the write ups on the subject. Thank you.
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      03-22-2018, 10:50 AM   #8
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Great write up! Is there a required procedure to reset the service menus in the car after this the brakes and wear sensors are replaced? Elsewhere in the forum some are saying that the sensors need to be "activated". Also, does anyone have the ITSA+ specifications for when the rotors need to be replaced?
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      03-22-2018, 12:47 PM   #9
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Nice write-up! I would make one addition right after: "The first time you get in the car, pump the brake pedal a few times until it's hard. It will likely press almost to the floor on the first press. Don't be alarmed." Add: "Now that the news pads are seated against the new rotors, double-check your brake fluid level in the reservoir and top off, if needed."
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      03-23-2018, 03:22 PM   #10
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Quote:
Originally Posted by JDuffy14 View Post
This is super helpful! just a few questions -
Does the same basic procedure apply for the rear?
How many sensors are there and where are they located (ill probably replace them when i do this)
why did you feel the need to quote the first post including all the photos. can you edit you post to eliminate that. its frustrating on mobile to scroll past the same photos on just the second post in the thread.
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      06-03-2018, 11:49 AM   #11
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Quote:
Originally Posted by Daggers View Post
I've done this a lot, but figured I'd document this for those that haven't changed their brakes before. I couldn't see a guide already. This applies to any car fitted with brembo 4 pot factory calipers (inc M sport/M Performance etc).

BMW quote 2 hours for this, which at £120 an hour at my local dealer equates to a LOT of money, plus the hassle of driving there at a time to suit them. Do it yourself - if you've not done it before you'll be surprised how easy it is, and it'll build your confidence with general maintenance.

Standard disclaimer - if you die horribly in a fireball or your wheels come off, or you hurt yourself because you dropped a brake rotor on your foot, etc etc, I’m not responsible. Notwithstanding that...

Difficulty rating:
2/10

Time required:
45mins - 1.5 hours depending on experience/confidence/how many cups of tea you stop for.

Tools Required:
Axle stands / jack.
1/2" Ratchet.
10mm & 17mm sockets.
HW6 socket (or 6mm allen key).
Torque wrench.
Breaker bar (useful, not essential).
1/2" Impact driver (again, useful not essential).
Drift/pin/modified screwdriver - for driving out the pad retaining pins.
Hammer.
Medium sized pry bay.
Small towels/tissues.
Small wire brush.
Brake cleaner.
Copper grease (copper slip).
Small brush (for applying copper grease).
Paper towels.
Small syringe.

!

Hello

A great post, a first M Perf specific. Lots of good videos, but yours is a true match for math tutorial. One thing that I wondered about is the L and R clips at the top of the pads. Are they necessary or is it BMW fool proof specific? Most replacement pads do not need them. You did not mention bleeding, how do you do it?

I notice the mint aspect of your rotor vents- orange-ish yellow rust. At the moment am completing the customization of the M Perf rotors and pads with a 3d strand woven carbon ceramic maker (there are four in the world), the new tech that works -40 to 1500C and lasts x3 longer than the old-CCBs (e.g. Brembo varieties on F80 etc). Once my first set is mounted, any 370x30mm owner can order one, a first, shaving some 15lbs per front rotor disc, or 30 total.

This change of direction happened despite having a replacement M Perf set standing by to mount, after watching and measuring rust rate, and also discovering the new tech leaving behind old CCB one (squealing, heat performance only, etc) hitting the market these past two years. In Canadian cities e.g. Montreal Ottawa and many more, they use 23% salinity per square m, twice sea level, and rotors last 3 years/2 winters whichever come first. With OCD care got my rotors to 78,000 kms at 29 mm (so 100,000 kms projection) mainly due to weekly car washes, but too much work and frequent bedding. Quite a few big brake kit owners loose a set before the end of the second winter. So we get full rotor flaking at a rate of 3000-5000 μm, several mm per 12 months exposure, or 1-1.5mm per 4 months of saline roads and winter. The vent area gets eaten, and the rust penetrates sagitally under the polished braking surface. Mainly as the outer circumference is so cold that it shrinks, and pas do not touch it for months betwene 0 and -40C, thus it never warms up and stayes wet and salty.

I guess in Southern US they loose tyres faster to heat, here rotor sets in 6 months of winter could be 2 winters three months of salt. Grand Cherokee and Range Rovers dish 2,000- 2,500 $ front sets so frequently). With CCBs will get 300,000 kms urban and monthly track, or more if inter city driving.

Note, Brembo steel is exceptional, so its corrosion rate is slower than cheap steel. But coming the 3d/4th summer, the rotor no longer cools uniformly due to mass changes, vent flaking and sagital perforation, I got 3 mm sagital, takes 10,000kms to polish that, but also seen it on other cars 1-2inches per front rotors. There is a way to rustproof rotors- industrial grade cadmium coating, on a prev car with Gt custom rotors, less than OEM cost, never lost a rotor set to any rust. After 5-6 winters, barely notice 0.5mm cumulative rust. Issue is that with our sets, they come zinc coated, which means they cannot be Cadmium-coated

great post BTW.

Last edited by Musashi; 06-03-2018 at 12:05 PM.
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      06-03-2018, 05:53 PM   #12
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Nice write up! Wrench away
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      06-06-2018, 10:37 AM   #13
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Thanks for this comprehensive guide. I've changed discs, pads calipers one numerous cars before but still picked up a few tips from this.
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      06-15-2018, 09:25 AM   #14
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Great post! Thank you for taking the time to put this together!
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      07-15-2018, 09:34 PM   #15
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Daggers thank you so much for putting this together. Without this guide it would have taken me all day to figure out those darn pins.
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