E46 BMW Social Directory E46 FAQ 3-Series Discussion Forums BMW Photo Gallery BMW 3-Series Technical Information E46 Fanatics - The Ultimate BMW Resource BMW Vendors General E46 Forum The Tire Rack's Tire Wheel Forum Forced Induction Forum The Off-Topic The E46 BMW Showroom For Sale, For Trade or Wanting to Buy

Welcome to the E46Fanatics forums. E46Fanatics is the premiere website for BMW 3 series owners around the world with interactive forums, a geographical enthusiast directory, photo galleries, and technical information for BMW enthusiasts.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

Go Back   E46Fanatics > Tuning & Tech > Motorsports & Track Forum

Motorsports & Track Forum
From Auto-X to Trackday to Racing and Professional Motorsports this is the place to discuss making BMWs fast

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 11-17-2008, 01:30 AM   #1
bigjae1976
Registered User
 
bigjae1976's Avatar
 
Join Date: Dec 2003
Location: Earth
Posts: 11,480
My Ride: A car
Send a message via MSN to bigjae1976
Brake fluid and soft pedal



I just completed my first driving school and it was awesome! I'm kicking myself for waiting so long.

Anyway, I have the UUC/Wilwood BBK upgrade. I ran with street pads and 8 month old ATE blue brake fluid.

This is probably a stupid question but on the third session, I my brakes suddenly got mushy. I checked after the session and I still have about 1/2 of the front and 3/4 of rear pads left.

So I am guessing that this is a brake fluid issue, correct?
bigjae1976 is offline   Reply With Quote
Ads by Google

Guests, get your FREE E46Fanatics.com membership to remove this ad.
Old 11-17-2008, 05:01 AM   #2
mkodama
Registered User
 
mkodama's Avatar
 
Join Date: Oct 2006
Posts: 33,172
I would also guess it's the brake fluid since it only happened after prolonged use.

8 months isn't too long, but over that time your brake fluid is going to absorb small amounts of water and its boiling temperature is going to go down...

From my experience, overheating the brake fluid gives a mushier feeling to the pedal while overheating the brake pads makes them smoke an lose some of their bite.
__________________

mkodama is offline   Reply With Quote
Old 11-17-2008, 09:04 AM   #3
bigjae1976
Registered User
 
bigjae1976's Avatar
 
Join Date: Dec 2003
Location: Earth
Posts: 11,480
My Ride: A car
Send a message via MSN to bigjae1976
Thanks! When I first started, I couldn't believe how badly I was beating on my car. I felt bad for her and was sure she would be mad at me later.

I guess the lesson here is to bleed your brakes and bring some fresh pads before you go to the track.

Last edited by bigjae1976; 11-17-2008 at 09:17 AM.
bigjae1976 is offline   Reply With Quote
Old 11-17-2008, 09:13 AM   #4
Lemonsqr
Registered User
 
Join Date: Sep 2003
Location: Chicago, IL
Posts: 3,134
My Ride: 2001 TiAg 330i
Quote:
Originally Posted by bigjae1976 View Post
Thanks! I guess the lesson here is to bleed your brakes before you go to the track.
Well if by "bleeding the brakes" you mean doing a complete brake fluid change, then yes. Getting rid of just some of your old brake fluid will not help the absorbed water or boil over problem. Usually "flush" = complete change of brake fluid and "bleed" = getting all the airbubbles in the brake line out. OK, I'll get off the soapbox.
__________________
Lemonsqr is offline   Reply With Quote
Old 11-17-2008, 09:24 AM   #5
bigjae1976
Registered User
 
bigjae1976's Avatar
 
Join Date: Dec 2003
Location: Earth
Posts: 11,480
My Ride: A car
Send a message via MSN to bigjae1976
Quote:
Originally Posted by Lemonsqr View Post
Well if by "bleeding the brakes" you mean doing a complete brake fluid change, then yes. Getting rid of just some of your old brake fluid will not help the absorbed water or boil over problem. Usually "flush" = complete change of brake fluid and "bleed" = getting all the airbubbles in the brake line out. OK, I'll get off the soapbox.
I meant flush.
bigjae1976 is offline   Reply With Quote
Old 11-17-2008, 12:36 PM   #6
aggieE46
Keep it clean
 
aggieE46's Avatar
 
Join Date: Aug 2006
Location: Royse City
Posts: 8,048
My Ride: 03 Evo, 07 Passat
Send a message via AIM to aggieE46
Glad you had a good time! I'm a bit jealous.

Did you ever get your CEL taken care of? How was the twinscrew on the track?
__________________
aggieE46 is offline   Reply With Quote
Old 11-17-2008, 01:40 PM   #7
flacoy2k
Registered User
 
Join Date: Jul 2002
Location: Coral Springs, FL
Posts: 467
My Ride: 2002 M3
I think the problem was your street pads. Yes it is true that fresh fluid meaning a flush a week or two before the event is best but 8 months old fluid should not be all that bad. Next time change your pads to a racing pad and it will be a night and day difference.
flacoy2k is offline   Reply With Quote
Old 11-17-2008, 02:22 PM   #8
teamdfl
Slow in, slower out
 
Join Date: Dec 1969
Location: Awesome, NJ
Posts: 4,572
My Ride: 325it
Quote:
Originally Posted by mkodama View Post
...8 months isn't too long, but over that time your brake fluid is going to absorb small amounts of water and its boiling temperature is going to go down...

8 months is too long according to every driving school tech inspection form I have seen in 10+ years of track experience. Every BMWCCA, PCA, and SCDA tech form I have filled out has required a brake fluid fluid flush withing 6 months of the track day.

You might be exceeding the capability of the street pads. You may also have knocked loose some random air bubbles from the last brake fluid change. Do a good fluid flush with a pressure bleeder or via the MODIC or GT1 computer at the dealer. Then go out and get the brakes VERY hot on a lightly traveled stretch of highway to see how they react.
__________________
Mod the driver. Participate in your local BMWCCA autocross or driving school. Have you joined BMWCCA yet?

teamdfl is offline   Reply With Quote
Old 11-17-2008, 02:46 PM   #9
vaio76109
Registered User
 
Join Date: Nov 2003
Location: Fort Worth, TX
Posts: 8,831
My Ride: Race Cars
Flush the brakes and get some real track pads.
vaio76109 is offline   Reply With Quote
Old 11-17-2008, 07:53 PM   #10
bigjae1976
Registered User
 
bigjae1976's Avatar
 
Join Date: Dec 2003
Location: Earth
Posts: 11,480
My Ride: A car
Send a message via MSN to bigjae1976
Quote:
Originally Posted by aggieE46 View Post
Glad you had a good time! I'm a bit jealous.

Did you ever get your CEL taken care of? How was the twinscrew on the track?
Nope, still have the CEL. I think I need a new MAF but I'm not getting my hopes up that is the only issue. I'm going to drop it off at my shop before I go to Korea. Then they'll have 14 months to fix it.

The s/c was bad@ss! Too bad I couldn't take advantage of all the power since my skills are still not that good and my brakes went soft the first day. The only thing I couldn't catch up to on the straights were the vettes. The car would definitely shoot out of the corners pretty quickly and really didn't have to shift a whole lot. I'm sure an LSD would help a lot.

Quote:
Originally Posted by flacoy2k View Post
I think the problem was your street pads. Yes it is true that fresh fluid meaning a flush a week or two before the event is best but 8 months old fluid should not be all that bad. Next time change your pads to a racing pad and it will be a night and day difference.
Quote:
Originally Posted by teamdfl View Post
8 months is too long according to every driving school tech inspection form I have seen in 10+ years of track experience. Every BMWCCA, PCA, and SCDA tech form I have filled out has required a brake fluid fluid flush withing 6 months of the track day.

You might be exceeding the capability of the street pads. You may also have knocked loose some random air bubbles from the last brake fluid change. Do a good fluid flush with a pressure bleeder or via the MODIC or GT1 computer at the dealer. Then go out and get the brakes VERY hot on a lightly traveled stretch of highway to see how they react.
Quote:
Originally Posted by vaio76109 View Post
Flush the brakes and get some real track pads.
Thanks for the info. I definitely underestimated the beating my car would take. I guess somewhat worn street tires didn't help either.

So my plan is to first flush the brake lines with some Motul RBF600 fluid.

As far as track pads, what would be a good option? I'm not trying to spend an arm and a leg and plan to track the car 2-3 times per year.

UUC's website lists:
Pagid
EBC
Hawk
Performance Friction
Wilwood PolyMatrix
Carbotech

Thanks

Last edited by bigjae1976; 11-17-2008 at 08:06 PM.
bigjae1976 is offline   Reply With Quote
Old 11-17-2008, 08:08 PM   #11
vaio76109
Registered User
 
Join Date: Nov 2003
Location: Fort Worth, TX
Posts: 8,831
My Ride: Race Cars
PFC-01's are the best pads I've used yet, but they're pretty pricey. I haven't used PFC06's yet, but they sound like they'd be a very good choice for you.
vaio76109 is offline   Reply With Quote
Old 11-30-2008, 11:11 PM   #12
bigjae1976
Registered User
 
bigjae1976's Avatar
 
Join Date: Dec 2003
Location: Earth
Posts: 11,480
My Ride: A car
Send a message via MSN to bigjae1976
Quote:
Originally Posted by vaio76109 View Post
PFC-01's are the best pads I've used yet, but they're pretty pricey. I haven't used PFC06's yet, but they sound like they'd be a very good choice for you.
Dumb question...those are performance friction, correct? Thanks for the input. What do you think of the Hawk DTC70's?

I just flushed my lines, what a difference! The blue brake fluid that I bled looked navy blue. I guess it was time. There still is no bite and I am just waiting on the pads to arrive.
bigjae1976 is offline   Reply With Quote
Old 11-30-2008, 11:59 PM   #13
delirium45
Registered User
 
Join Date: Mar 2007
Location: Longmont, CO
Posts: 1,067
My Ride: 2004 M3
Yes, PFC-01 is Performance Friction's most aggressive track pad currently. The PFC-06 is similar but less torque and is designed to last longer, good for enduro racing (ie: 13hour+ races).

I ran Hawk HP+ in my 330i, they did pretty well, but if you have a supercharger you may be going a lot faster... i tried the HP+ on my M3, and they just laughed at me when i asked them to stop me. I will be dressing with PFC-01 for next season.

As far as fluid, superblue is just fine, do a full flush, i use a pressure bleeder to flush, then have someone pump the pedal afterwards and do a final bleed with them, this usually gets everything old and bubbly out.

Good luck !
__________________
_ Garrett

2011 Rocky Mountain Region GTS4 champion & "Rookie of the Year"
2012 Rocky Mountain Region GTS3 champion
Thanks Sponsors: SCR Performance & Built-by-Bones
delirium45 is offline   Reply With Quote
Old 12-01-2008, 12:19 AM   #14
vaio76109
Registered User
 
Join Date: Nov 2003
Location: Fort Worth, TX
Posts: 8,831
My Ride: Race Cars
Quote:
Originally Posted by bigjae1976 View Post
Dumb question...those are performance friction, correct? Thanks for the input. What do you think of the Hawk DTC70's?
Yes, Performance Friction. I haven't used the DTC-70's, although I did use HT-10's for a while. For a first track pad they're decent, but PFC-01's really blow them out of the water. It's one of those things that you don't know what you're missing until you try it.
vaio76109 is offline   Reply With Quote
Old 12-01-2008, 09:15 AM   #15
bigjae1976
Registered User
 
bigjae1976's Avatar
 
Join Date: Dec 2003
Location: Earth
Posts: 11,480
My Ride: A car
Send a message via MSN to bigjae1976
Quote:
Originally Posted by delirium45 View Post
Yes, PFC-01 is Performance Friction's most aggressive track pad currently. The PFC-06 is similar but less torque and is designed to last longer, good for enduro racing (ie: 13hour+ races).

I ran Hawk HP+ in my 330i, they did pretty well, but if you have a supercharger you may be going a lot faster... i tried the HP+ on my M3, and they just laughed at me when i asked them to stop me. I will be dressing with PFC-01 for next season.

As far as fluid, superblue is just fine, do a full flush, i use a pressure bleeder to flush, then have someone pump the pedal afterwards and do a final bleed with them, this usually gets everything old and bubbly out.

Good luck !
Quote:
Originally Posted by vaio76109 View Post
Yes, Performance Friction. I haven't used the DTC-70's, although I did use HT-10's for a while. For a first track pad they're decent, but PFC-01's really blow them out of the water. It's one of those things that you don't know what you're missing until you try it.
The PFC-01s don't seem to unreasonable. I think that's what I will be ordering. Thanks for the info.
bigjae1976 is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Censor is ON





All times are GMT -5. The time now is 05:42 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
(c) 1999 - 2011 performanceIX Inc - privacy policy - terms of use