tarmacrdr

Hi everyone,

First, I did a search on this topic but could not really find a definitive answer to my issue. And I do not post very frequently so my apologies in advance...

So here how it goes...

Before my track event, I changed my pads to EBC yellow stuff and replaced my brake fluid with Motul 660. I bedded the pad to my rotor before the event. Braking was just fine for the first 15 mins into my track session, then suddenly my brake pedal went really soft/mushy. I noticed that if I reapplied, the pressure would build up and pedal travel would be back to normal. So I thought it was an air issue on the brake line. So I went back to my Indy and bled the line. Now it is all normal. My concern/question is will I experience a similar event during an other track event as I cannot really generate similar high temp braking on open traffic. The initial flush was all done properly, one corner at a time, starting from the furthest one. The reservoir was never low enough to get air inside.We used up a total of nearly 2 liters of Motul 660. The brake fluid is a pretty decent one with high boiling temps. So I would like to rule out the boiling of the fluid.

Looking for your suggestions,

Thanks folks

cosm3os

You boiled the brake fluid.

swartzzz

Are we certain that the they bled the calipers from BOTH bleeders? Could this be a need of the clutch slave needing bled? Not sure, just asking.

Ohio Performance

I'm going with air bubble.

nwGTS

Yeah, guessing you boiled. What was ambient temp? Watch dragging the brakes at the track. That will glaze your pads and boil your fluid in no time.

tarmacrdr

Thanks for all your replies. I do appreciate them all.

I saw them connecting the tube to both sides of the caliber.

Regarding boiling the fluid; I thought motul 660 which was the replacement from the factory fluid was supposed to have a higher boiling temp. My driving was mot too different than before when I was with the older fluid. The air temp was around 25c/77f so it was not the air temp.

So since then the line has been rebled, shall I expect boiling of the fluid if I drive the same way.? Shall go back to the previous brake fluid, which I think was inferior? I am going to get GT2 air ducts, perhaps that would also help with cooling the brakes, but not sure if this will help with brake fluid boiling.

Thanks for the input again folks

Quadcammer

I say pad fade. yellowstuff go to crap when u get them hot hot

Petza914

Unless your braking technique is very poor, unlikely you boiled Motul 660 fluid, especially if you haven't had that issue tracking previously. I would rebleed also doing activations of the ABS pump just to make sure there's not air trapped somewhere. If it was trapped in the ABS circuit it might not have been moved to the lines or calipers until you activated the ABS during the track event. If that was the case, the second bleed should have taken care of it, but that assumes you got it all out of the ABS system. If not, it could happen again, which is why I say use a Durametric or PIWIS to bleed the ABS circuit to make sure there's no air in there, then bleed the lines again.

I've never run EBC yellow pads so can't comment on them, but if they get hot and glazed causing you yo apply more force for longer time that could put excessive heat into the calipers.

linderpat

I ran EBC Yellow and Motul 600 on my Mustang at track, and I love those pads. Never once had a problem with them going soft on a very hard driven, heavy front end car with many hot sessions. Running Pagids on the 911, but may go back to EBC Yellow Stuff again for next set. Your braking issue sounds like what Pete said.

tarmacrdr

Great - thanks guys.

I will try to initiate the ABS pump and see if I get any air in the system. I know it may not be good enough, for now till I get it to my Indy for the Durametric bleeding...

Quadcammer

depends how fast you're going and how hard the track is on brakes. Green or blue driver, probably fine.

tarmacrdr

Hi Ed,

When you get a chance, can you share your feedback of Pagid vs YS? Pagid RSL29 was on my next pad list. I think YS is easier on the rotors than Pagid, but I do not have any datapoint with Pagids.

Thanks,

tarmacrdr

The track is VERY VERY hard on any brake. It is the Formula One track in Istanbul. I tend to trail brake occasionally due to traffic and other reasons, so use my brakes heavily. But I came off the standard OEM pads to YS. I do not think the pads were the issue.

cosm3os

Are you leaving your stability/traction control on?

TrackDays247.com

Hmm...EBC Yellow stuff....so many problems I am VERY SURPRISED at the positive comment on them here..let's put it that way