Brake Locking Problem
 

I have been having this problem where i start driving and maybe about 5 mins after, the brakes start locking up and then stick shut, and the ABS light turns on) Then, the brakes dont unstick unless i do the ecu reset (via the brake pumping method). If you have any idea why or how the brakes could be locking up that would be really awesome.


Im running (if this helps the diagnosis at all):

Stock Greddy Turbo Kit - running the emanage
Brembo Gran Turismo Big Brake Kit (front only)
Borla Exhaust
TurboXS Midpipe
AEM electronics(Boost and AFR)

I have concluded that:
-I'm not throwing any CELs regarding the brake system (only ones regarding my cat deleted midpipe)
-The problem is not the emanage since i am currently running the car NA (turbo not piped into the throttle body, just a straight intake).
- Also i do not see any leaks where the stainless steel lines meet the brake fluid feed line
-Also As far as i can feel, the hardline for the brake fluid does not have any kinks in it.

If anyone can come up with any issues or any reasons why this could be happening that would be pretty awesome.

bump, anyone out there?

so many things could be doing this. Your brake bias is WAY off if you have only the front big brake kit on? Dont know if would have that pronounced of an affect to cause your root problem.
I wouldnt drive it until fixed.
the ecu reset like that shouldnt have any affect on the brake electronics. Its probably just the rapid pumping thats clearing it. maybe air in line--close to abs system?
let us know.
OD

Goose, do you know if it is the front or back brakes that are locking up? One, two, three, or all four locking up? Have you tried to bleed out the lines?

When did you put in the front brake kit?

brake kit has been on for awhile, well over 6 months i believe. only now the problem is happening

maybe this bit of information might help:
-we JUST finished the install of the turbo
-the car has been up on jack stands for about a month.

the brake system ran fine since ive had it up until this point.
I cant tell if the rears lock up but the fronts def do. After (painfully) getting it back onto my driveway, the front rotors/calipers/pads are hot as sh!t whereas the rear brake area is only mildy warm, causing me to believe that only the fronts are locking up, as far as i can tell.

We have re-bled the lines but the problem occurs again.

One of my guesses could be that maybe its electronic based, since the locking up generally happens about the same time every time (a few mins after driving), regardless of brake usage(a lot of braking vs minimal braking). I will say though as i start using the brakes after a fresh reset, as you use it more, you can feel the pressure buildup and the brake pedal gets tighter and tighter.

At this point i wanna diagnose what makes the brakes lock up like this or why would the brakes lock and stick like this, what could cause them to do so.

sorry i don't know offhand, but how does the e-manage interface with the stock ecu? is it a pnp harness or was their any sort of splicing involved? this could be something electrical due to the e-manage wiring, maybe a short?
..... or you mightve fubared something up mechanically while working on your car ... have you checked the abs module in the engine bay? follow the lines down, maybe you hit something during the install

well the emagane has a harness that plugs into the ecu, then also has a female end where the stock harnesses go into. Its a piggyback system. no splicing or cutting involved.

We checked the hardline for kinks but didnt find any. Also, wouldnt a kinked hardline only affect that one brake(since theyre all independent)? And i have at least both fronts locking up.

The braking system seems fine as far as i can tell. I've actually unplugged the emanage piggyback and just running the stock harnesses back into the ecu (back to NA style) and have the throttle body go straight out to intake(pretty much running the car NA again, and the problem still occurs, so im eliminating the kit itself as a cause for this failure. Also, i dont thnk ive seen any other emanage users have a problem with the piggyback fighting with the stock ecu and mess up the braking system. but who knows...

still trying to think of causes why the brakes would lock up and stick..and esp after the same amount of time every time..


im really appreciating the feedback btw, its helping the brainstorm.

screwed up wheel sensor causing the abs/tcs/dsc to lock down?


but no i think- if you are positive there are no kinks in the hard lines- that you have either a bad booster or master cylinder

if its a bad booster or cylinder, maybe its coincidence that it happened after my install or maybe sitting on the stands for a month maybe had something to do with it maybe?

oh yeah which ever it turns out to be I am assuming you broke something during the time it was on or coming down from the stands :D:

FOUND THE PROBLEM.

Well whoever reinstalled the strut bar, (its mazdaspeed), overtightened the master cylinder brace, therefore causing it to push the fluid unit in and effectively making a "kink" in that area. Once i loosened the brace from the strut bar, the fluid unit visually moved back out a unit and i did hear some fluid seeping back into the master cylinder.

Thanks all for your feedback and ideas, I have been scouring through the brake manual in the workshop manual for countless hours lol. But thank you zoom for mentioning the master cylinder, or else i mightve not thought about what was affecting that area.

Thanks again all :)

I've said it before and I'll say it again.... GOOSE STOP BREAKING SHIT!!! We have a meet in two days!!

if i can get my boost under control ill be there.

do it! do it NAAAOOOWWWW!!!!