[ThomasR]

Just the rears. I'm starting on the fronts tomorrow.

[ThomasR]

Ok so I got the fronts done the following weekend and then drove on them easy the first 150 miles are so per BMW recommendations. I tested them a little after that and they seem better than stock however initial bite is not.

So today I have a story to tell. We have a stock '09 335i. Our first BMW, and ordered new by us from the factory like the X3 was. Initial brake bite and overall braking in that thing have always been fantastic. About 3-4 years ago she got tired of the stock brake pad dust and I put Akebonos on it. Initial bite and overall braking suffered but eventually we both got used to it. They are still on the car today. (Also I must say the brake dust problem *is* gone)

Last Monday, with 133k original miles on her stock injectors and coils she punched the 335i around some traffic on the way home and the car went into limp mode for the remaining 5 miles home. I diagnosed it as a stuck injector. I ordered 6 new ones along with new plugs and she drove the X3 to work from Tuesday through the rest of the week while I waited on the parts to come in late Friday. I put the injectors in this weekend and her car is back like new.

She called me this morning after getting to work to say how well the engine was running smooth but also how much better her brakes(crappy Akebonos still!!!) feel compared to mine. (I didn't ask her to compare BTW)



I guess one day when I get *some* mileage out of these stock BMW $$$$ pads I'll look for some aftermarket pads that have COLD HIGH initial bite.

[agent_orange]

Just had an interesting experience with brakes that relate to what ThomasR found as well.

Since my 2011 F25 with 183,000km is just starting to get unreliable, I bought a 2014 one with m-sport, lots of options and only 50,000km to replace it.
The newer one still had OEM BMW discs and pads and when I picked it up I was very surprised at just how decent the brakes were at normal town driving speeds, especially initial bite which I think was actually slightly better than that on the 2011 one with big brakes front and rear.
Figured out pretty quickly that my impression of the stock brakes being dismal was due to the cheap generic aftermarket 'low dust' pads that were on the 2011 one when I bought it.

Had already planned before even buying it to swap the big brakes to the newer car and the stock brakes to the older one to sell it with, so carried out the 2x installs and ISTA bleeds the other week, but did wonder whether I had wasted a fair bit of $ on the big brakes.
They do work better under harder braking from higher speeds and/or downhill where the stock ones go a bit wooden past the high initial bite, and dust is virtually zero with Carbotech 1521 pads I keep telling myself to justify it...

ThomasR, I would have thought that with BMW pads you would not have lost initial bite like you did find?

[hardparker]

Yeah, I played with various pad brands and formulations around 15-20 years ago and eventually settled in on EBC YellowStuff. I've run those on every car I've owned for the last 15 years and really like them. They dust like hell, so either get black wheels, ceramic coating or live with it. I could care less regarding the dust. If anything, it makes me feel good seeing it there, knowing that I've got excellent stopping power under all conditions.

The only complaints I've ever heard of them are in extreme cold, well below freezing, where apparently some people say they feel a little glassy until they come up to temp. All of those cars were left outside, though. I suspect they may have been put up wet and water froze between the pad and disc and took a bit to melt.

The other extreme was in full on track day sessions with cars that really merited a full on track/race pad. For daily driver pads and some dust, YellowStuff is awesome. Some folks like RedStuff better for less dust, but they just don't perform as well overall as YellowStuff.

Oh, and just to tuck in this tidbit somewhere, the LCI F25 master cylinder is 27mm, 2mm bigger than the 2011-2014 models. Accounts are that it improves pedal feel with bigger brakes over the original 25mm version.

[agent_orange]

Not keen on anything EBC having tried them as well many years ago.

That is interesting about the LCI master being 2mm bigger.
I've fitted larger master cylinders to many previous cars (not BMWs) so know what it does.
Will give a higher bite point assuming the non-adjustable pushrod gap doesn't increase with the swap, firmer pedal, and less travel, but actually decreases braking power per pedal effort. So it's good to have a decent amount of braking power before upgrading.
I'll keep a look out for a low mile master cylinder for sale, but having just done ISTA bleeds on 2 cars I'm not keen on doing it again for a little while.

[ThomasR]

I feel a whole lot better about the upgraded brakes now. I have had some situations where I've had to really lay into them and they give me 100% confidence that I have more than enough. My rear calipers (bought reman'd) are starting to have some surface rust. The fronts were taken from an X5 with less than 40k so they are fine. One day I'll take care of the rust.

I do love the way the rotors fill in the wheels.

[januarysnake]

hardparker so far think this is the most practical post on upgrading brakes for a F25.

Got a 2017 X3 xdrive28i and want to upgrade the brakes a bit. sorry for all the questions. new to the bimmer world and trying to figure stuff out as I go...

From what I'm reading, the two-pot calipers off a F15 50i are the way to go heh.

If I can't find good used scrap calipers, would you say this is the complete parts list for the F15 50i front brakes?

https://www.getbmwparts.com/v-2015-b...--front-brakes


and with the bolt kit you posted on Ebay, should be good to go.

and looks like these will clear 19" stock BMW rims?

[hardparker]

Originally Posted by januarysnake

hardparker so far think this is the most practical post on upgrading brakes for a F25.

Got a 2017 X3 xdrive28i and want to upgrade the brakes a bit. sorry for all the questions. new to the bimmer world and trying to figure stuff out as I go...

From what I'm reading, the two-pot calipers off a F15 50i are the way to go heh.

If I can't find good used scrap calipers, would you say this is the complete parts list for the F15 50i front brakes?

https://www.getbmwparts.com/v-2015-b...--front-brakes


and with the bolt kit you posted on Ebay, should be good to go.

and looks like these will clear 19" stock BMW rims?

For X5 50i calipers, the Centric 14134111 (right) 14134112 (left) remanufactured calipers are pretty widely available and cheap. They do clear my stock 19" wheels no problem.

[januarysnake]

Originally Posted by hardparker

For the 50i combo, the parts are:

1 x Caliper housing left 34116788431
1 x Caliper housing right 34116788432
2 x Caliper carrier 34116788433

I'd recommend buying used calipers from ebay, though. They average around $60 per caliper from the online auto recyclers there. The ones I bought looked in good enough condition to use, but I went ahead and bought rebuild parts from RockAuto.com and rebuilt them myself, which was pretty quick and easy.

hey hardparker when I look for the calipers housing using the BMW numbers above, I get calipers related to the X6 series (E71 or E72 or F16) https://www.getbmwparts.com/oem-part...er-34116788431

cross-check and it does apply to the X5 series too.
http://bmwfans.info/parts-catalog/34116788431

Didn't read that this would be a X6 series calipers too, so just want to make sure I'm looking at the same thing.

Apologies... first time digging for parts on a BMW parts :s

[hardparker]

Originally Posted by januarysnake

hey hardparker when I look for the calipers housing using the BMW numbers above, I get calipers related to the X6 series (E71 or E72 or F16) https://www.getbmwparts.com/oem-part...er-34116788431

cross-check and it does apply to the X5 series too.
http://bmwfans.info/parts-catalog/34116788431

Didn't read that this would be a X6 series calipers too, so just want to make sure I'm looking at the same thing.

Apologies... first time digging for parts on a BMW parts :s

Yeah, those same calipers came on X6es as well as X5s. Both E and F series.

[addy27]

For those who have ventured into the f10 rear brakes, there is another possible option to get the 370x24 rotors onto the rear. I have an f10 and am about to put the 370x24 rotors on but the caliper/carriers are straight off of an M5 without any custom brackets. They bolted right up (https://f10.5post.com/forums/showthr...1488894&page=9)

I'd encourage if someone with an x3 can confirm it too. What you would still need are the washers/spacers to position the caliper/carrier centered to the rotors, but that is something that is a known factor here.

Looking forward to hearing/seeing someone here try this combo.

[agent_orange]

That is very interesting about the M5 calipers bolting onto F10 with the 370x24 rotors addy.
When I was trying to reverse engineer the rear caliper fitments in theory from car data (part numbers, rotor sizes etc) and also the different Tronik adapters, I did find that the F10 M5 calipers or just their brackets/carriers if you already have 345x24 spec F10 calipers, could be a possibility.
They were a bit too expensive with shipping to Australia to buy just to test fit and possibly find that they didn't fit, but will now keep my eyes open for some carriers.

The F01 370x24 caliper carriers should also bolt straight onto F10, but the F10 24mm caliper with park brake motor won't go onto those carriers at all due to a different location of the slide pins and different brand of calipers, ATE vs TRW.

[a4j]

Awesome job

[a4j]

Also How did you jack the car? did you use jack points? Did you use the differential as a jack point? I am wrking on the brakes and your response will be a huge help.

[bmwPower99]

Hi Guys - I was going to be a guinnea pig for 18" wheels but thought I'd check the forums for X5 50i owners who wanted to run 18" Rims for winter tyres. The link below seems to show that 18" tyres do not clear!

https://f15.bimmerpost.com/forums/sh....php?t=1454976

[rcsup1]

Originally Posted by a4j

Also How did you jack the car? did you use jack points? Did you use the differential as a jack point? I am wrking on the brakes and your response will be a huge help.

You can use either.

[nyceric03]

Originally Posted by bmwPower99

Hi Guys - I was going to be a guinnea pig for 18" wheels but thought I'd check the forums for X5 50i owners who wanted to run 18" Rims for winter tyres. The link below seems to show that 18" tyres do not clear!

https://f15.bimmerpost.com/forums/sh....php?t=1454976

I also have a f15, it seems like most 18"s won't clear the 50i calipers, but I had one set that did just barely, safer to go with 19"s. See pics in link below, I ended up with 19" winters for the f15, and put the 18"s on e70

https://f15.bimmerpost.com/forums/sh....php?t=1398235

[januarysnake]

Originally Posted by hardparker

For X5 50i calipers, the Centric 14134111 (right) 14134112 (left) remanufactured calipers are pretty widely available and cheap. They do clear my stock 19" wheels no problem.

took a break from the upgrade idea but I think this is the year for both the front and rear brake upgrades on the X3 F25

could I bother you a bit to see if I got my shopping list right?

FRONTS:
- Centric front L & R reman calipers you suggested above.
(No extra caliper brackets needed right? the part number includes the right bracket for the upgrade)
- "calipers on the 550i are trailing mount, behind the axle, rather than the X3's leading mount." mount opposite to the X3's. - any modification necessary?
- 365x36 front rotors (any brand that fits a F25 X5 xdrive50i) and pads to fit the Centrics and these rotors
- upgrade X3 braided stainless lines brake lines (and you noted X3 pad sensor work without issue on the X5 calipers)
- your ebay listing for "BMW F25 X3 F26 X4 brake upgrade adapter kit for X5, X6 brakes" custom milled spacers
- trim heat shield

want to confirm, X3 braided stainless brake lines and original X3 pad sensor should work on these X5 50i Centric reman calipers?

am I missing anything else for the front upgrades?

REARS:
- F10 550i reman calipers (Centric 141.34611 and 141.34612)
- 345x24 rear rotors (for a F10 550i right?) with matching pads
- you say "Stock X3 brake line and pad sensor works fine" for the rears, correct?
- "parking brake actuator and hose bracket transfer over to the 550i calipers easily."
- "There are spacers for lateral offset correction." these are the spacers? https://www.ebay.com/itm/254550397143
- "One edge of the heat shield needs to be snipped or bent back."

if I upgraded to braided lines I can get F25 X3 rear braided and should work on those Centric 550i calipers?

Do I need spacers in the rear like the ones you have for the fronts?

Am I missing anything else for the rear upgrade?

appreciate this thread!

[hardparker]

Originally Posted by januarysnake

took a break from the upgrade idea but I think this is the year for both the front and rear brake upgrades on the X3 F25

could I bother you a bit to see if I got my shopping list right?

FRONTS:
- Centric front L & R reman calipers you suggested above.
(No extra caliper brackets needed right? the part number includes the right bracket for the upgrade)
- "calipers on the 550i are trailing mount, behind the axle, rather than the X3's leading mount." mount opposite to the X3's. - any modification necessary?
- 365x36 front rotors (any brand that fits a F25 X5 xdrive50i) and pads to fit the Centrics and these rotors
- upgrade X3 braided stainless lines brake lines (and you noted X3 pad sensor work without issue on the X5 calipers)
- your ebay listing for "BMW F25 X3 F26 X4 brake upgrade adapter kit for X5, X6 brakes" custom milled spacers
- trim heat shield

want to confirm, X3 braided stainless brake lines and original X3 pad sensor should work on these X5 50i Centric reman calipers?

am I missing anything else for the front upgrades?

REARS:
- F10 550i reman calipers (Centric 141.34611 and 141.34612)
- 345x24 rear rotors (for a F10 550i right?) with matching pads
- you say "Stock X3 brake line and pad sensor works fine" for the rears, correct?
- "parking brake actuator and hose bracket transfer over to the 550i calipers easily."
- "There are spacers for lateral offset correction." these are the spacers? https://www.ebay.com/itm/254550397143
- "One edge of the heat shield needs to be snipped or bent back."

if I upgraded to braided lines I can get F25 X3 rear braided and should work on those Centric 550i calipers?

Do I need spacers in the rear like the ones you have for the fronts?

Am I missing anything else for the rear upgrade?

appreciate this thread!

Spot on with all of that. Parts are all correct. The Centric reman calipers include the brackets. Stock lines and sensors work. Front and rear spacer kits from me on ebay and you're good to go! You'll really enjoy that brake upgrade. I still really love mine. One of the best mods on the car.

Note that the rear calipers mount opposite of 550i; left on right and right on left. The fronts mount to the normal sides. Just make sure the bleed nipples are all facing up and you'll be fine.

[najnad]

Has anyone got objective numbers on how much decrease in stopping distance any of these combinations have over stock? I would hate to spend $$$$ for only modest improvements.

[agent_orange]

Have now done about 13,000km on the front and rear big brake setup since swapping it to the 2014 car, and still pretty happy with it.
When I swapped the rears from the 2011 to the 2014, I ditched the Porterfield R4-S pads as they dusted like crazy, were chewing up the discs, and gave too much rear bias.
Put Carbotech 1521 pads in there, the same compound as the front and had the rear discs machined.
Due to the very low-wear nature of the 1521s plus machined discs, it took thousands of kms for the rear brakes to bed in and reach peak effectiveness.
Overall the system is pretty good now, despite my considered choice to run pads with a much lower friction coefficient than the fairly good OEM ECE R90 and GG-friction rated pads.

Has anybody had any success with DSC coding to get a higher and/or more effective pedal?
The F30 and F15 guys can do it (usually for M sport or M perf brake upgrades) and apparently makes quite a noticeable improvement.
F25/F26 didn't have any OEM or M perf brake hardware variation though other than the slightly larger F26 M40i fronts, unlike other models that had 3,4,5 different disc and caliper combinations, which could limit DSC coding options.

[hardparker]

Yeah, still super happy with that brake setup myself. The last time I did a long coding session, I made a pass through all of the DSC options and saw a few things that I tried modifying, but they made zero difference. I've been meaning to revisit it, but haven't gotten around to it yet. It doesn't help that my old laptop set up for coding is long gone now.