Well...


"Mastercylinder failure symptoms include a brake pedal that slowly depresses when pressure is applied. Other signs include a lack of any braking action until the pedal is pressed against the floor."

That's why I asked what happens when you push it down at a standstill. Master cylinders do fail on these cars. Ask me how I know....

Although it's less likely to be the culprit, it's the one that will bite you the biggest.

 

Yeah, no such symptoms, fortunately.

 

having driven various BMW's in DD, autocross, and HPDE's, which use the same calipers (or various sizes of), I can't tell the difference in feel between calipers with stock guide bolt bushings or the bronze bushings. I can definitely tell the difference between different pad compounds and stainless lines make the biggest change.
And like Charlie said, you don't want the pedal to go more than 50% of the distance to the floor as that would make heel/toe more difficult.
If the brakes aren't doing anything when you first start pressing the pedal, like a rental car does, that again points to either air bubbles or disc runout.

Use up your current tires before buying new ones...lesser tires are a good way to learn your car's characteristics at and over the limit of traction, take advantage of that.

 

OK, gotta throw my 2 cents into this one...
Had the exact same experience...Carbotech 1512 street pads versus Carbotech XP10s. Same wheels, tires, rotor, calipers, shocks, springs, brake fluid (flushed) - you get the picture.
The 1512's were spongy, had no grip and were very frustrating. I had to stand on them to just slow the car down well enough alone get on the ABS. On the street they seemed great but not for autoX.
The XP10s were solid, great grip (even slightly warm) and great modulation - yes, I know, this are a track pad and not an ideal autoX pad but they are light-years above the street pads.

So - my vote - get a good set of pads, not the green or red stuff, go spend the big bucks on the yellow stuff, Hawk HP+ (both of which I have used - much better than stock or stock-like pads) or, better yet, the Carbotech AX6. Then bleed the brakes again.

 

Whoa wait so you're saying the EBC red stuff pads aren't any good? There's plenty of people saying otherwise. Or are you just talking about open track pads?

Either way your experience is good to know - that different pads can give a totally different feel, sometimes an undesireable one.

 

Nope, not saying the Red Stuff are not good. I have no experience with them for autoX, but have seen them used on the track without success. In that respect they may be fine for autoX. Mostly wanted to let you know my experience with different levels of pads that seemed to be the same as yours. And to suggest options of pads I would choose for autoX based on that experience. Hope to just provide some limited insight and hope it helps.

 

Definitely - and your experience with the different pads is good because there's so much information flying around about different pads when there's obviously other factors involved like rotor condition, fluid, and application, ie autocross or open track. I think if I was going for open track use I'd consider a step up from the red stuff. For autocross, a setup closer to OEM has many supporters.

 

UPDATE: So I put together the advice I've received from experienced auto-x'ers and track drivers both on NAM and in person (shout out to Ron at C2 Motorsports in San Diego!), and I think I'm satisfied with the results. Note that I am not trying to build an all-out track-only car where brake ducts, SS lines, massive brake kits and atmospheric re-entry capable brake fluid are a no-brainer. That being said, here's the summary of my experience:

I have an R53, and after my first autocross event with OEM brakes, ATE blue fluid, greenstuff pads (and old rotors), and Achilles (cheap) tires, I felt that the car's stopping power was inadequate. See above posts for definition of "inadequate."

I purchased 4 calipers off an R56 from the NAM marketplace (thanks again!), and expecting to do a full R53-R56 conversion, I also bought parking brake cables and SS lines.

It ended up that the rear R56 calipers wouldn't fit (surprise, surprise) without considerable grinding that I didn't want to do. This was because the SS line bolts (even with the correct banjo-bolt fitment) as well as the parking brake cable ends were hitting the trailing arm in multiple locations, and I didn't have the time, tools, or confidence to make it work, especially since it's common knowledge that the rear R56 OEM brakes offer little or no improvement over rear R53 OEMs.

So after way too much time wasted (stupid parking brake removal - by the way, a 12mm socket can be used to release the clips from their spot behind the e-brake), I reverted back to R53 rear brakes with the OEM lines.

The front R56 calipers were a joy to install. So easy. My joy was met with pain when I found out that I had been sent the wrong SS lines (banjo instead of straight). And of course I had to find this out after I had installed the SS lines on the hard lines of the car with my awesome newly purchased flare-nut wrench set. I was attending an organized cruise in 2 days, so I didn't have time to exchange the lines, and being July 4th, nobody was open. On July 5th, I called EVERYWHERE about brake lines, and ended up going with OEM lines from the dealer, and simply returning the SS lines and parking brake cables.

Since the hard lines had been exposed for a couple days (I did the brake pedal trick, though, to keep air from creeping up the line), I wasn't sure if my R56 caliper install with Red stuff pads had gotten all the air out of the system (this was after bleeding). I took the car to Mini of San Diego to get an ABS-activated flush. (Side-note: Bill at Mini was EXCELLENT, informative, friendly, and met me at my level of knowledge with the car, not afraid to go outside of the world of OEM lol)

Before my track day at Streets of Willow, I did another bleed, and did some more bedding of the redstuffs.

The pedal feel after this seemed to match what's been described all over the forums - "soft" with pedal travel I wasn't confident about, and no massive bite that sends your head into the windshield. I was worried about this going into the track event. I think part of it is an expectation that "better calipers" + "performance pads" + "performance fluid" = a fly can land on the brake pedal and the car body will be torn from the chassis. In reality, I think that the "pedal feel" when you're driving around town freaking out that your new pads suck is quite different from "pedal feel" when you're flying around the track slamming the pedal over and over - you kinda forget about that "in-town pedal feel."

STREETS OF WILLOW TRACK DAY:
If you didn't read everything above, I went to Streets of Willow with the following brake setup:

OEM brake fluid
Dealer brake flush
One bleed (post brake flush)
R56 front calipers (practically new)
R53 rear calipers
OEM brake lines (new front)
Redstuff front pads (new)
OEM-grade rear pads (new)
Centric front rotors (new)
OEM-grade rear rotors (new)

and...

Track day was a success! The brakes were great! When slamming on the brakes and heel/toeing from 60-90mph down to 30-40 mph, the brakes felt JUST RIGHT. In previous posts I described the old brake setup as not inspiring confidence, but this setup gave me all the confidence I needed, all day long - 4 sessions of about 9 laps each. They felt just as strong at the end of the day as they did the first lap.

As an extra side note, I had the only Mini at the event, and one of the only FWD cars. My lap times were very consistent, and for one of the sessions I got the fastest time in my class.

At this point, I'd say I'm happy enough with the brake performance that I'm now certain that the tires need to be upgraded. As a whole, the Mini was so balanced! I was truly surprised at how there wasn't any one aspect of the car that manifested itself as a weak link - it's as if all the performance characteristics of the car reached their limit together, very organically. I had been afraid that I'd experience what I've seen in the past (and with other cars), where you know the car is being severely handicapped by only one item - really frustrating when you know the car is being held back by something obvious.

I don't have many pics (there weren't any photographers at the event this time ), but I have a couple on my Instagram @akafrozone (by the way, does no one have IG? Or post to #northamericanmotoring? Come on, now!)

So thanks again to all who helped me get to my current setup. I think I'll be happy with it for a good while.

 

Glad it all worked for you

 

I understand and agreed with what Eddie has said in his previous posts. The point is that you don't seem to be going fast enough right now on the track for it to matter much. But when you do pick up some speed, and have to use more brakes, you will start to understand what he has described. This comes from experience and seeing the incorrect brake pads catch fire on the track and/or boiling fluids.

 

Um, yeah, I'm pretty sure that based on the tracks I've taken my cars to, that I won't be "going that fast for it to matter much" and that my pads won't catch on fire. That's why I explained numerous, numerous, many times on this thread (not just since Eddie chimed in with his experience), what kind of application I was searching for. That's why I specifically did *not* go with yellow stuff.

 

I understand. Just talking about what might be ahead. We might want to push the limits eventually.

 

FWIW - In other threads discussing brakes and brake fluid, Way of WMW has reported strange pedal feel with the ATE Blue, he recommends Motul for Minis.

I just changed to Motul RBF600, so far the brakes feel great, I'll get the chance to see how they work on the track week after next.

 

Just reporting back that I bled the brakes yesterday (for the first time since Streets of Willow, see above posts). I used the Motiv Pressure bleeder for air pressure only, not pushing fluid through the bottle.

I used a syringe to remove as much of the old fluid in the reservoir. There was clearly some ATE blue left in the system (I was kinda ticked that a "full flush" from the dealer, including the ABS activation procedure, didn't completely remove the blue, but I understood that it would have had to pay for a second flush to do so).

I filled the reservoir nearly to the brim with OEM fluid, attached the Motiv and pressurized it to 15 psi.

Went to the RR bleeder screw, loosened it, and....
bubbbbbbbbllllllesssssss.

At this point, it was if all the NAM posts were echoing in my head: "bleed, then bleed again, then drive, then bleed again...." I just had no idea how true that would be - I mean, where did all the air come from?

Repeated on RL brake, bubbles, then depressurized the Motiv to add more fluid to the reservoir. Re-pressurized and bled FR and FL brakes. Bubbles.

Removed the Motiv and poured the remaining fluid into the reservoir. Used one OEM bottle to complete the above procedure.

I've been driving a bit since then, and the first thing I noticed was that the brake pedal seemed to respond higher. I don't want to exaggerate or anything, but compared to the "soft" feel where no usable braking could be felt til the pedal was about 50-60% depressed, the pedal now seemed to provide usable braking power much further up, very linear.

Thanks NAM and all who posted on this thread. Having some sanity after months of driving and way too much spent on brake fluid sure is nice.

 

I believe I have seen posts from WMW that he has seen multiple cases of soft pedal pressure with Super Blue fluid.

 

Notwithstanding, as posted above, I was experiencing a soft pedal feel with OEM and Motul. The obvious culprit was just needing to complete repeated bleeding over time; it wasn't the fluid.