I would like some opinions on this one.

I migrated to Hawk HPS pads this year for my HPDE schools. I was having problems last year with stock pads/brakes on my R56 MCS where as the day progressed, the brake pedal would get progressively spongy as the day went on. Good braking still but pedal getting soft and moving farther.

I was hoping that maybe the new pads would help. Although they did work good, I was still experiencing a soft pedal towards the end of the day (6 - 25 min sessions).

Any of you experienced this ? Is it just that the stock brakes are not up to the challenge or do I have a mechanical problem ? (master cylinder ?)

 

Bleed your brake lines with fresh high temp fluid. You probably boiled your fluid causing the spongy feel.

 

Are the pads still biting and just the pedals is spongy? If so this is fluid, flush with ATE super blue/ type 200 and you'll be fine (just rember to bleed the breaks every few months if you track often)

If the pedal feels like a block of wood (no matter how much force you give her she ain't slowing down) then that's pads, in that case bring a set of HT-10's or DTC-60's (at least for the fronts) with you and change them at the track (all you need it a 7mm allen and a c-clamp, doesnt take long at all)

 

Thanks guys for the feedback.

rpob5t: The pedal feels spongy but lots of braking available. I am thinking that it's indeed the fluid. A flush was performed by the shop during tech inspection but they put the standard fluid in. I thought it might be ok...

I have some fresh ATe in hand. I'll do a thourough flush before going back to the track in July.

So what I'm hearing is that the standard calipers on the R56 MCS will work fine. I don't want to spend 2 grand on a big brake kit....

 

yeah you definately don't need a BBK on you're car, just decent pads and fluid. What you're running on street tires should last you a while, if you're starting to get some pad fade (another sign of this will be excessive pad wear, overheated pads get burned up quickly) then I'd go to a higher friction pad (what I reccomened before is what I've used on my E30 with its tiny brakes and have never had a braking issues on track tires).

if youre on hoosiers and starting to melt down track pads, then a BBK might be something to look at for perfromance reasons (though operating costs might be another thing to consider if you plan on doing a lot of this stuff, the wilwood pad shapes tend to be a bunch cheaper and bigger than OE sizes)

 

Good ! I'm glad to hear that.

Maybe I went a little too conservative with my pad choice by going with Hawk HPS. Maybe I should've gone with something more agressive as your suggestion below. I'll wear these ones out and migrate to something a little more aggressive for next time.

 

Hello All,

I just recently changed my rotors and pads on my 03 Mini S. I pressure bled the system twice with ATE super blue. The brake pedal still feels a little spongy (you know not like when it came from the dealer). According to the bently manual, you need an OBD II diagnostic tool to place the car in abs/dsc service mode. I don't have that tool. I'm thinking because I didn't use that tool that thats the only thing that could have kept that spongy feeling. What are your thoughts?? Any advice is much appreciated.

 

Never used OBD II tool when bleeding the brakes. If they are spongy there is still air in the line - assuming no leaks.

Alan

 

Thanks for the response. I'm sorry I should have given more detailed info. The tool I was talking about was not the OBD II tool, however you do use the OBD port on the car. I was refering to the Dimsport plus, GT1 computer that the bently manual instructs us to use. From what I have found the computer system is exclusive to mostly BMW dealerships, and it puts the car in ABS/DSC service mode. This mode supposedly allows the ABS system to cycle while you bleed the brakes. I'm not sure what the benefits are from this. I have to agree with you there must be some air still in there. I will most likely bleed and re-bleed again. I want to thank everyone for your insight and expertise. I would rather have a little air in the line than to pay the dealer $800+ dollars. Just my humble opinion

 

I have an R56 and have always had good luck using a Motive Pressure Bleeder http://www.jscspeed.com/universal/products/motive.htm . However, I was at the track just this weekend and was talking to a friend who said that because of the ABS, in order to bleed his 06 BMW Z4 M, he has to pump up the pressure bleeder up to 25lbs pressure. (The pressure bleeder says to only go to 20lbs). A BMW mechanic told him to do this and that 25lbs will do no harm. The mechanic also told him that as an alternative, he could pressure bleed them at 20lbs but would then need to the drive the car and make the ABS kick in, and then go back and pressure bleed them again (and maybe even a third cyle). But the mechanic said there was really no point in the 2nd alternative method because 25lbs would not hurt anything.
My friend has pressure bleed his brakes serveral times at 25lbs and says it always works great.

 

I actually had some improvement with the brakes. The stiff pedal feel has come back at least half again. The next time I bleed them I will give it a little more pressure. (I bled mine at just around 15 lbs). Thanks for the tip. By the way I wish I would have bought the motive bleeder instead of the Bavauto one. It is built good but, you do not have the option to buy adapter caps or have one custom made for different master cylinders. So the only thing I can bleed with the Bavauto one is just the Mini Cooper S DOHHHHHH!!!! later gators

 

Yep - try more pressure in the bleeder.

FWIW - AutoEnginuity with the BMW extensions will also allow you to do the ABS bleed - just did mine yesterday. While not cheap, $431 to buy AutoEnginuity is cheaper than dealer brake jobs.... and lets you do almost everything the GT1 can do (except coding). Lots of diagnostic capability.

 

Auto Ingenuity you say eh. I think I have a new tool on me list. My wife is gonna kill me lol!!!! Thanks for the advice and the heads up.

 

BTW, I suspect you'll soon find, if you've not already, that the HPS pads are not up to the task of DEs. I fried a set of HPS pads 1/2 way through a DE this past weekend - they simply are not made for such conditions. In my case, they began glazing badly and going off quickly. Just getting into DEs, thought I'd be able to use the relatively new HPS pads for an event or two - didn't quite work out that way From what I've learned, sounds like Porterfield R4 or Carbontech xp10/xp8 are the way to go in the stock calipers.

Regarding fluid, I've had decent luck using the motive bleeder and alternating ATE Blue and ATE amber fluid prior to each event.

 

Well guys, I was at the track last weekend and can report that the HPS pads didn't make the cut. The brake cooling ducts helped a bit, but the pedal was still getting soft towards the end of the day.

I met a couple of guys with highly modified R53's, one of which was an instructor, and they both confirmed what jblow just indicated: Carbotech XP10 and 8 is the way to go.

I have some on order with new rotors. I'll be testing again at the Glen in late August.

The Quest continues....

 

I too have had good luck with the Carbotech XP10 and 8 combo.
They squeal too much if you try to leave them on and use them on the street. You also have to bed the pads in to the rotors.
I have an extra set of rotors that I swap out each time I change the pads. By matching up the pads with their respective rotors, I don't have to re-bed them in each time. It only takes another couple of minutes to switch out the rotors when you are changing out the pads.

 

I have been using the Carbotech XP10/XP8 combo. I am thinking of moving up to the XP12 fronts and XP10 rear combo. Anyone with experience with those?

 

Slinger688: actually, I just checked my order, and the XP12/10 was in fact recommended by Dustin at AutoXCooper (not 10/8) as I originally thought. This was based on specific questions he had regarding what type of tires, what run group, level of experience.

I'll let you know how this combo works out.

 

mlg2ca,

Great. Let us all know.

How did your brake duct kit hold up on the track? I got mine from Morristown Mini a couple of weeks ago but have not yet installed it.

 

It held out no problem. Since the ducts are jammed in between the grill and the radiator wall, it has no where to go.

I think it helped overall but not enough on it's own. It all comes down to using the proper pad combination.

I'll be at Watkins Glen last week of August with the GVC BMW CCA.

 

Good to hear about the brake ducts. I will be following your example.

WGI is still one of my favorite tracks, especially in the NE. I hope to meet you at one of these track events one day soon.

Are you planning any other track days this year other than wgi?

 

No, technically this will be my last school for the year. I did Calabogie Motorsport in May and last weekend. I try to do about 3 schools/yr. I hear that the Montreal chapter does a school at Mt-Tremblant in September, so I might consider it.

What are your plans ?

 

I try to do 12-15 HPDE days a year. These are my next few:

Monticello, NY July 31 SCDA
LRP August 10 SCDA
NJMP Sept 14-15 SCDA
LRP Oct 31 SCDA

You can tell I like SCDA because they give you a little more time on the track but they are a little expensive. I was just at wgi July 13-14 with SCDA and they ran 2.5 hours a day. A bit tough on the car though but real fun for the driver.

 

Whoa ! Too much for this old man !

With the BMW clubs, we get about an hour a day track time (4 x 30 mins) which is plenty for me. I find at the end of the day, last session, time to watch out for the red mist.

Have fun and keep the rubber on the track.

 

I really feel tired after 2 1/2 hours. I am no spring chicken either, having retired last year into the financial mess in the NE.

If I have the budget, I may show up the the GVC WGI event.