Rock Hard Brake pedal in the middle of an autocross run... - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

Jedi1 · 01-17-2013, 02:24 AM

Has anyone else gone for the brakes and gotten nothing but a rock hard pedal and almost zero slow down?

I had a Mk4 R32 VW that would do this if you barely got into the ABS and then tried to modulate the brakes to balance the car. If you barely touched the ABS while while working the brake pedal it would go hard as a rock and do nothing to slow the car.

Had this happen at a test and tune autocross a month or so ago in the FRS. It has only happened one time and I just can't remember the circustances leading up to the incident. Just curious if anyone else has experienced this and if they know the exact cause.

Thanks for any info you can provide.

CSG Mike · 01-17-2013, 02:50 AM

Do this: http://www.ft86club.com/forums/showthread.php?t=25494

Jedi1 · 01-17-2013, 03:01 AM

I was wondering if that would cure the problem. I will be trying it the next time I'm at an autocross or on track. Does that kill the ABS though?
Thanks for explaining your experience with and without the "Pedal Dance". I will be trying it out!

CSG Mike · 01-17-2013, 03:08 AM

ABS will still be there.

whataboutbob · 01-17-2013, 03:14 AM

Yes. I'm gonna try to do the "pedal dance" as noted in the linked thread.

d1ck · 01-18-2013, 10:29 AM

Sounds like "Ice Mode". It's happened to me before and I don't know if it's a fault with the design of ABS systems or an actual mode which is programmed. Pull the ABS fuse if you're afraid it will happen again.

xwd · 01-18-2013, 10:46 AM

Unfortunately in the classes we run in you can't pull the fuse.

I'm not sure the pedal dance will defeat this or not but maybe it will if the function is built into the brake force distribution system...

I used to have a good spot with some broken up pavement I could get the ice mode to kick in 100% of the time on my WRX. I have yet to encounter ice mode with the BRZ with or without the pedal dance.

Jedi1 · 01-18-2013, 03:11 PM

I have not heard or seen anyone else taking about it in regards to the FRS/BRZ. Figured I would throw this out there so folks would be aware it is possible in these cars and hopefully get some advice to keep it from happening in the middle of a National Event Winning Run! Dream big or don't dream at all! Lol. Thabks for the advice given regarding the issue. Can't wait to try it out.

rice_classic · 01-18-2013, 09:40 PM

I did the pedal dance today but I wasn't in my car. Should I consult someone?

Getagrip · 01-20-2013, 05:51 AM

Quote:

Originally Posted by Jedi1

Has anyone else gone for the brakes and gotten nothing but a rock hard pedal and almost zero slow down?

I had a Mk4 R32 VW that would do this if you barely got into the ABS and then tried to modulate the brakes to balance the car. If you barely touched the ABS while while working the brake pedal it would go hard as a rock and do nothing to slow the car.

Had this happen at a test and tune autocross a month or so ago in the FRS. It has only happened one time and I just can't remember the circustances leading up to the incident. Just curious if anyone else has experienced this and if they know the exact cause.

Thanks for any info you can provide.

I had this happen to me more than once last season.
I will be doing the "pedal dance" from now on.

Simmons · 01-20-2013, 10:27 AM

Quote:

Originally Posted by Jedi1

I have not heard or seen anyone else taking about it in regards to the FRS/BRZ. Figured I would throw this out there so folks would be aware it is possible in these cars and hopefully get some advice to keep it from happening in the middle of a National Event Winning Run! Dream big or don't dream at all! Lol. Thabks for the advice given regarding the issue. Can't wait to try it out.

I posted about it a couple times already, it happens to me Alot. It seems more if there is a bump before the turn, or a quick change in direction before braking. DO NOT remove the abs fuse, I tried it and all it does is lock up instantly. The pedal dance does not work in my at least, I tried it a couple times and it never activaties. I left foot brake, I think that makes it happen easier. This season, I am going to try to Not left foot brake to see what happens. It is Very scary when it happens, I am always looking for corner workers and light poles hoping I can stop in time. I found the best way to deal with it is, when it happens let off the brake and start your turn it seems to work every time.

Simmons

IMOA · 01-20-2013, 11:11 AM

If it's the same problem that jedi1 also experienced in his MkIV R32 it's in the software of the abs unit so it's quite unlikely that pedal dance will help. There was quite a bit of investigation in Australia around this problem in the Golfs about 8 years ago and my understanding is that it the problem occurred when getting a wheel in the air under heavy braking (but not every time when a wheel was in the air). Is this happening to people only during autocrosses (maybe slower speeds and bigger direction changes which lead to wheels being picked up?) or has it happened to people on a racetrack as well?

Jedi1 · 01-20-2013, 12:54 PM

I have never experienced it on the street and only twice on a proper race circuit. It gets fairly exciting in the car when you are at the point of turn in and there's a bit of trail braking to do at the limit. Boom! NO brakes when you need them the most! Not Cool!

xwd · 01-20-2013, 02:23 PM

Quote:

Originally Posted by Simmons

I posted about it a couple times already, it happens to me Alot. It seems more if there is a bump before the turn, or a quick change in direction before braking. DO NOT remove the abs fuse, I tried it and all it does is lock up instantly. The pedal dance does not work in my at least, I tried it a couple times and it never activaties. I left foot brake, I think that makes it happen easier. This season, I am going to try to Not left foot brake to see what happens. It is Very scary when it happens, I am always looking for corner workers and light poles hoping I can stop in time. I found the best way to deal with it is, when it happens let off the brake and start your turn it seems to work every time.

Simmons

One thing to keep in mind with the "pedal dance" is the car has to be completely warmed up, and I would guess it is based off the coolant temp. If it's not warmed up completely it won't work. I practiced a couple times after getting to/from work and it never failed. I can do it faster than holding the button down for 3 seconds.

Whether it works for this or not, I kind of doubt it myself but others have mentioned it helped a lot with trail braking at least on road courses.

01-18-2013, 09:40 PM	#9
rice_classic Senior Member Join Date: Jun 2012 Drives: Nevermorange FRS Location: Seattle, WA Posts: 4,173 Thanks: 757 Thanked 4,208 Times in 1,808 Posts Mentioned: 78 Post(s) Tagged: 1 Thread(s)	I did the pedal dance today but I wasn't in my car. Should I consult someone? __________________ SCCA T4 - FRS

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Redline360: Brake Lines, Brake Rotors, Brake Pads for BRZ/FRS	Redline360	Brakes, Suspension, Chassis	12	01-05-2013 11:20 PM
Rattle from the middle of the car	brichard0625	Issues \| Warranty \| Recalls / TSB	11	10-05-2012 08:04 PM
Odd brake pedal feel, fade?	yomny	Suspension \| Chassis \| Brakes -- Sponsored by 949 Racing	27	09-11-2012 01:29 PM
First Whiteout 86 in the Middle East	i_giado	Member's Car Journals	26	07-09-2012 06:30 AM
Anybody near Middle Indiana	AX_FRS	Tracking / Autocross / HPDE / Drifting	17	06-02-2012 12:16 AM

01-17-2013, 02:50 AM	#2
CSG Mike Join Date: Jul 2012 Drives: S2000 CR Location: Orange County Posts: 14,562 Thanks: 8,942 Thanked 14,211 Times in 6,854 Posts Mentioned: 970 Post(s) Tagged: 14 Thread(s)	Do this: http://www.ft86club.com/forums/showthread.php?t=25494

01-17-2013, 03:08 AM	#4
CSG Mike Join Date: Jul 2012 Drives: S2000 CR Location: Orange County Posts: 14,562 Thanks: 8,942 Thanked 14,211 Times in 6,854 Posts Mentioned: 970 Post(s) Tagged: 14 Thread(s)	ABS will still be there.

01-18-2013, 10:29 AM	#6
d1ck Senior Member Join Date: Jul 2012 Drives: Black 2013 FRS Location: Newfoundland Posts: 249 Thanks: 31 Thanked 83 Times in 54 Posts Mentioned: 2 Post(s) Tagged: 0 Thread(s)	Sounds like "Ice Mode". It's happened to me before and I don't know if it's a fault with the design of ABS systems or an actual mode which is programmed. Pull the ABS fuse if you're afraid it will happen again.

01-18-2013, 10:46 AM	#7
xwd Senior Member Join Date: Feb 2012 Drives: 2013 DGM Subaru BRZ (Subie #9) Location: ATL, US Posts: 2,667 Thanks: 123 Thanked 861 Times in 552 Posts Mentioned: 32 Post(s) Tagged: 0 Thread(s)	Unfortunately in the classes we run in you can't pull the fuse. I'm not sure the pedal dance will defeat this or not but maybe it will if the function is built into the brake force distribution system... I used to have a good spot with some broken up pavement I could get the ice mode to kick in 100% of the time on my WRX. I have yet to encounter ice mode with the BRZ with or without the pedal dance.

01-20-2013, 11:11 AM	#12
IMOA Member Join Date: Jan 2013 Drives: 86 GTS Location: Sydney Posts: 40 Thanks: 0 Thanked 22 Times in 12 Posts Mentioned: 1 Post(s) Tagged: 0 Thread(s)	If it's the same problem that jedi1 also experienced in his MkIV R32 it's in the software of the abs unit so it's quite unlikely that pedal dance will help. There was quite a bit of investigation in Australia around this problem in the Golfs about 8 years ago and my understanding is that it the problem occurred when getting a wheel in the air under heavy braking (but not every time when a wheel was in the air). Is this happening to people only during autocrosses (maybe slower speeds and bigger direction changes which lead to wheels being picked up?) or has it happened to people on a racetrack as well?

User Name		Remember Me?
Password