werid braking

[gelo]

this happened at the last session of the ozhodna trackday
and it hasnt happened before even with my stock ek4 brake set up ( stock pads and fluid)

ive recently upgrade to this brake set up for track:
prelude rotors
dc2r calipers
ss brake lines
stock dc2r pads (new)
dc2r brake booster and master cylinder
motul rbf600 fluid

at the 2nd corner at wakefield
4th gear going 150+
i woudl need to shift down to 2nd
as i heel toe'd form 4th down to 3rd
my brakes sank to maybe 3/4 of the ground with a very weak brake force
and when i blimped hte throttle while in neutral
nothing happened
the car felt like it was just rolling along

this happened 3 times in that session all at the 3rd corner, otehr corners were fine
on the 3rd time
i actually pushed it into 2nd gea as the revs dropped and let go of my clutch
and the revs didnt come back up as the gears engaged
i had to double clutch it back into 3rd to get the revs up

this has the symptoms of a brake lock up
except i didnt, didnt feel any lock ups, no tyre noises or smoke

[roar]

well after you've changed all that stuff...it may be pedal related...so the driver input side of your braking system may be rooted

i'm only guessing

[destrukshn]

maybe it's your lines?

[EuroDude]

So the accelerator pedal didnt work, plus the brake pedal?

Maybe something is caught in the pedal mechanics, causing them to stick intermittently. Or maybe something like a coke bottle got jammed under the pedals.


Or maybe your mind was rushing and your foot was shaking, that it gave the impression that there was something wrong with the car :D

[Slow96GSR]

Check the connections, check fluid levels, bleed the lines, repeat, then check 1 last connection.... driver! Do some math too, make sure the booster isn't too big. Also check vacuum and the lines too.

[zco]

all of your suggestions may solve his problem. but i still dont get why.. it would happen on that corner only, but not any other corner

[|N|]

shiet.. i think its haunted ... but gelo ... would that be anything to do with left and right turning
?

[fatboyz39]

check fluid level, bleed the brakes again.

IF that doesn't help then either booster or MC are shoot.

[gelo]

yeah thanx guys
prob try to bleed the brakes again and see ho i go

[BlitZ]

my brakes sank to maybe 3/4 of the ground with a very weak brake force
and when i blimped hte throttle while in neutral
nothing happened
the car felt like it was just rolling along


i don't know if this can happen, but ive read something like this on honda-tech..
I cant remember the fix but the issue was and could be now:

the brakes release too much as they cool down, running down the straight,, so when u come to use it they are too far off and you require extra pressure to squeeze them (thats why pedal to the metal)


..

[bennjamin]

AFAIK the brake fluid viscocity changes as it heats up...and cools down again.
So , under extreme braking the fluid heats up and takes more pressure to allow the same leverage , and once it cools down abit its "fine"...