Guide MS3 front brake conversion

Yay! MR6 approved!

I'll say it again, if anyone needs to do rotors AND pads, there is NO reason not to upgrade.

LOL. For the record, my wife approves too ;)

That's great to hear.
How is the pedal feel? (I can't remember and I'm too lazy to search - is the MS3 piston larger? If so the pedal should be softer, but by how much... ?(shrug))



You know, except for cost. :p

just bustin balls, I know what you mean.

The pistons are the same size.i believe it was Mr. SilentNoise himself that did the leg work.

The pedal feel is better than on my newer speed which has the exact same setup save for the lines. Its interesting to be able to accurately note how much the SS lines have really improved the pedal feel! Maaaybe a half inch of dead space before the tasty initial bite kicks in.

I should note that they're grabby as hell first thing in the morning. Goes normal after few hundred feet though.

And yeah, you know, cost is definitely a consideration. I'll edit this post later with exact costs but i wana say in the neighborhood of 500 clams. Ive paid triple that so relatively cheap for a "BBK"!
 
Piston ID are the same. I didn’t pop the piston out to measure OD but RockAuto lists the same caliper repair kit so...

I’d call this a bBK (mini b) :D. When it comes to cost, it depends on how much you want to scrooge. Really the only added cost are the calipers w/brackets, which were <$180 for me and it came complete with slightly used OE pads and hardware. You can retain the stock rubber lines and you will be buying new rotors, pads, and should be doing new fluids anyway. These costs should not be considered since they are maintenance items either way –MS3 rotors/pads have a slight mark-up over Mz5 parts. I do agree this might not be an option for everyone as not everyone is willing or able to invest the time or money and there's added cost if they have to get it installed, which should not be bad in labor rate. I bet naysayers will have a change of opinion after getting a first hand (err, foot) feel.

MR6’s experience is exactly like what I went thru. From the pain points, to the first experience that promoted his updated post (my first update reads almost exactly like his), to his comment about the aggressive tip-in, which I did NOT like at first but thankfully that smoothed out after ~700 miles and a 2nd bleeding. I used Napa SBs and I don’t think I bleed them completely the first time.
 
Last edited:
Yeah the aggressive tip-in is already starting to smooth out nicely. I was on the highway without the fam today and brought her up to 100 and clamped on them before the exit...just to test, of course. She scrubbed off speed immediately and tracked straight as an arrow with just a tiny bit of dive as i leaned her into the off ramp with barely any zero lean. It was glorious. Amazing how all the mods have shrunk her down. This lil van needs a turbo to match all this stop and turn prowess she's got now (rockon)

And the cost of the brake conversion was $535 + knick knacks like the rebuild kit, brake line clips, etc. I updated the 'My Vehicles' page here http://www.mazdas247.com/forum/garage.php?do=user_garage_view&id=58795
 
Last edited:
Yeah the aggressive tip-in is already starting to smooth out nicely.

Mine are the same. The first time I went around the block I had a WTF moment. They've settled down quite a bit and I've gotten used to them also. Never had a car with such responsive brakes. They still feel FANTASTIC. Initial bite is awesome, very progressive after that and easy to modulate.

You can do the fronts for pretty cheap actually from RockAuto. Order caliper P/N 14145112 and 14145111. They are reman MS3 calipers and come with the brackets. $54 each. Core is $80 each but that is refunded when you send your old calipers back WITH the old brackets. You MUST send back the brackets! Pick your pads and rotors of your choice. Potentially do this upgrade for as little as $300 total.
 
that's pretty cheap. Are the RockAuto calipers OEM reman or knockoffs? In other words, do they have "ATE / FoMoCo" stamped on them?

I'm surprised they accept Mz5 calipers as core for MS3 calipers...
 
that's pretty cheap. Are the RockAuto calipers OEM reman or knockoffs? In other words, do they have "ATE / FoMoCo" stamped on them?

I'm surprised they accept Mz5 calipers as core for MS3 calipers...

They are OEM reman. All original logo's are there. The tag in the box only stated that you had to return the caliber brackets with the calipers and the tag had to be attached to the brackets. It did NOT say that had to be the SAME brackets..... (sssh) I followed the instructions as written.

-edit- Was thinking that even if they didn't give you the core back you are still only looking at about $275 for reman calipers with brackets. Not a bad price to get something ready to bolt on. Just add the cost for pads and rotors of your choice.
 
Last edited:
That's awesome. If they want the same cores back they need to say so! lol. I always assumed RockAuto calipers were china knock-offs. That's good to know. I maaaaybe saved $30 going junk yard. Not worth it. Would've saved me a heap of time & trouble though I probably wouldn't have broken them down & painted them pink. And that's obviously the sexiest part of my mod ;)
 
They are OEM reman. All original logo's are there. The tag in the box only stated that you had to return the caliber brackets with the calipers and the tag had to be attached to the brackets. It did NOT say that had to be the SAME brackets..... (sssh) I followed the instructions as written.

-edit- Was thinking that even if they didn't give you the core back you are still only looking at about $275 for reman calipers with brackets. Not a bad price to get something ready to bolt on. Just add the cost for pads and rotors of your choice.
Haha, technicalities win! :D This is a GREAT deal for the next person who’s looking to do this, even if you don’t get the core refund. Did you have a good look over to see what they replaced (Pins, boots, seals, bleeder valves, hardware kit, dirt/grim free)? These little things add up in cost and time! If come time needing a rebuild, it just might be worth paying the $50 but I guess it depends on what they replaced (not worth it if it was only the seals).

I don’t think there will be too many stock MS3 remains out there so take advantage while there’s stock. OTOH, since they received your calipers as the MS3 core it may very well be sold as such to the next person :(
 
You can do the fronts for pretty cheap actually from RockAuto. Order caliper P/N 14145112 and 14145111. They are reman MS3 calipers and come with the brackets. $54 each. Core is $80 each but that is refunded when you send your old calipers back WITH the old brackets. You MUST send back the brackets! Pick your pads and rotors of your choice. Potentially do this upgrade for as little as $300 total.
whoah. thanks for this!
 
Haha, technicalities win! :D This is a GREAT deal for the next person whos looking to do this, even if you dont get the core refund. Did you have a good look over to see what they replaced (Pins, boots, seals, bleeder valves, hardware kit, dirt/grim free)? These little things add up in cost and time! If come time needing a rebuild, it just might be worth paying the $50 but I guess it depends on what they replaced (not worth it if it was only the seals).

I dont think there will be too many stock MS3 remains out there so take advantage while theres stock. OTOH, since they received your calipers as the MS3 core it may very well be sold as such to the next person :(

They looked pretty well done over. Seals and boots looked new. Didn't see any dirt or defects. Even a little dab of grease in the pin guides.

I've been in several rebuild facilities in the past. A lot of them just checked that something was received then everything goes in a big pile for tear down and cleaning. Common parts are grouped for inspection and repair (pistons, guide pins, etc...) The item specific parts are then sorted (caliper body, bracket, etc...) for inspection. They are then reworked on a component level before reassembly. The only times I've seen them check if an item received was proper were for high dollar items or serialized products.
 
Think 16" OEMs will clear the larger calipers? I know MS3 folk can run 16" steelies in winter, so it seems like it should work.
 
i sold the stock 17s without fitting them over the calipers. sorry guys i have no idea.
 
You mounted the brakes and drove it around to test before removing to paint again but never tried the stock wheels? Oy. I guess the world may never know lol. Funny thing is my snow wheels might have more clearance than stock and be less of an issue. You did check if the spare still fits right?
 
You mounted the brakes and drove it around to test before removing to paint again but never tried the stock wheels? Oy. I guess the world may never know lol. Funny thing is my snow wheels might have more clearance than stock and be less of an issue. You did check if the spare still fits right?
I though I give you my input. The MS3 caliper bodies are bulkier as in they protrude more. The issue really is the OE rim itself. It has a high offset and the rim/spoke design is too flat, particularly at the bends. The spoke rubs the caliper body, making it IMPOSSIBLE to mount the rim to the hub. You need spacers to push the rim out just a tad, about <.25”ish. There is NO clearance issue concerning the inner diameter of the rim to the caliper. I’m 99.9% sure 16” will fit (there's lots of space), barring some freaky combo of high offset+spoke design.

Good questions on the spare. I too had concerns on the spare specs and found that the MS3 donut is different -double check jimellismazdaparts.com. Nonetheless, this is not a problem. If a front tire go out, just swap in a rear tire and put the donut in the rear. You shouldn’t be driving with a donut on a drive wheel anyhow –that’s my excuse and I’m sticking to it. To be honest, I still occasionally check craigslist for RX8 spare :X


EDIT: Can't see the spacer in this pic but you get the idea that it can be made to work fine. NOTE: technically I can only say this applies to '08 but realistically '08-'10 since these years uses the same rim design. '06-‘07 and +'12 are different so they may or may not have issues.
img1033b.jpg
 
Last edited:
I could live with a 1/4" spacer if thats all it takes. Thanks for that info. My snow tires have a freakish amount of room for the brakes, I'll post a shot later but they seem to be able to fit any brakes you could think of! On my other car, 3000GT VR-4 and source of my forum name, I upgraded to a later versions brakes that were much bigger and did not clear the factory spare. I figured it out by testing and was able to get the spare tire that went with the brakes. I would agree with you about the spare on a drive wheel but only if it were a long highway run. I would never take the time to change both on the side of an interstate anyway, it would wait til I'm off the next exit. Oh and with the VR-4, all 4 wheels are driven. On that car, there is a limited slip rear diff so its probably best to keep it on the open front diff if anything.
 
You mounted the brakes and drove it around to test before removing to paint again but never tried the stock wheels? Oy. I guess the world may never know lol. Funny thing is my snow wheels might have more clearance than stock and be less of an issue. You did check if the spare still fits right?

(loser) I know. stooooopid! I assumed they wouldn't fit just from all the forum hearsay. I really should've tested it. We still have TonyC working on a conversion though.

I though I give you my input. The MS3 caliper bodies are bulkier as in they protrude more. The issue really is the OE rim itself. It has a high offset and the rim/spoke design is too flat, particularly at the bends. The spoke rubs the caliper body, making it IMPOSSIBLE to mount the rim to the hub. You need spacers to push the rim out just a tad, about <.25”ish. There is NO clearance issue concerning the inner diameter of the rim to the caliper. I’m 99.9% sure 16” will fit (there's lots of space), barring some freaky combo of high offset+spoke design.

(iagree) see. hearsay. i read it on a forum, it must be true lol

Good questions on the spare. I too had concerns on the spare specs and found that the MS3 donut is different -double check jimellismazdaparts.com. Nonetheless, this is not a problem. If a front tire go out, just swap in a rear tire and put the donut in the rear. You shouldn’t be driving with a donut on a drive wheel anyhow –that’s my excuse and I’m sticking to it. To be honest, I still occasionally check craigslist for RX8 spare :X

Think 16" OEMs will clear the larger calipers? I know MS3 folk can run 16" steelies in winter, so it seems like it should work.

Those guys buy MS3 spares. I used mine once. It has a HUGE, HUGE outward bulge around the circumference to clear the caliper. It's the weirdest looking spare i've ever held. I was planning to do what Silent suggests and just move the rear to the front when it happens.
 
Here is my clearance on the snow wheels:

IMG_20140306_162012960_zpsbknsqy1o.jpg



This is on the stock first gen 17's:

IMG_20140306_161841856_zpsixe1dtvc.jpg


I dont have photos of my wheels and they aren't installed yet for the season.
 
You can do the fronts for pretty cheap actually from RockAuto. Order caliper P/N 14145112 and 14145111. They are reman MS3 calipers and come with the brackets. $54 each. Core is $80 each but that is refunded when you send your old calipers back WITH the old brackets.
update: apparently all you crazies have been buying up MS3 calipers from rockauto, cuz 14145112 (driver side) has been out of stock for weeks. 14145111 (pax side) is down to the final 1 after I got mine today.

Also of note, JC Whitney has a 10% off code, putting 1415112 at $63.88, 1415111 at $59.9, shipped FREE. However, JC Whitney charges tax, so YMMV; also, their core is $98 instead of $80. I ended up going with Rockauto for pax, JCW for driver. Rockauto's core is handled 10min away from work so I split the orders up. ANYWHO.

(loser) I know. stooooopid! I assumed they wouldn't fit just from all the forum hearsay. I really should've tested it. We still have TonyC working on a conversion though.
lolz. I have a '12+ with 17"s, and the clearance is nothing like twinturbo's gen1 17s. I guess I better have 5mm spacers ready. The point might be moot since I've been hunting for RPF1s and Miata CS rims. Maybe I'll have a set in my hand when I do the brakes.

Finally, it really hurts me to have to install the "upgrade" since the car is literally brand new. I don't know... Seems really wasteful. And the wife would eat my nuts tartare style. We shall see.
 
Back