short vid of me almost dumping it in turn 1

[Jayspeed]

I had what felt like brake failure. I rode the front straight and began my hard braking before turn 1. It was fine at 1st but as I continue squeezing the brake lever all the sudden, the brakes feel like they let go while still having pressure at the lever. Only thing to do is turn and go wide to scrub off some speed. I spoke with several people about this and have found several things that may have happened. The question here is what could have made this brakeless feel so abrupt? Old brake pads? No, wouldn't this be a gradual decline in quality braking power. Boiled the brake fluid? The brakes worked fine afterward as I finished the lap(which I did very slowly). Glazed brake pads? I'd have to check them out which I haven't had the chance yet but still they felt fine afterward. Maybe my slipper clutch kicked in and so I lost some engine braking? Possible. Maybe I semi locked the front tire and slid on the front tire for a brief second. I'm thinking this may have happened. Anyways, I'm trying to figure this out because I'd like to avoid this ever happening again. Any input much appreciated. I'm managed to get this on camera and posting this hoping the culprit could be revealed. Thanks for the info to those I spoke with about this. At the 9 second part, you can see my front end wiggle. I believe this is when the problem happened. At the 12 second part the front gets a nice jolt from the crack in the pavement which at the time felt like slip and thought I was going down. This video does't give justice and it appears like it wasn't that bad but the feeling of no brakes when you need them most is a shitty feeling. One thing I've learned from this is I think I can enter turn 1 10mph faster than I thought was fast.
YouTube - Turn one at loudon almost dumped

[davemon]

Are you certain you didn't have the throttle open a little bit when you got on the brake hard and thought you were off them? I've done that two or three times and it feel like the brakes just aren't working. I rode out into the dusty parts of T3 once to "do some scouting" so I could tell others how yucky it is out there.

Dave

[Tricky Mike]

Dunno Jay, Seems unlikely that you locked up the front (based on what I've heard about the physics involved), Way to keep your head and ride it out.

[e30addict]

Dunno what happened, but keep in mind if turn 1 get overcooked you can always use the oval as an escape route without trying to force the turn. That little gap in the tire barriers is great for the same reason going into 3.

[DucDave]

I think it is possible that it was boiled brake fluid....it can cool pretty quickly and you may never have it happen again. I am sure someone more expert than me can tell you about the different brake fluids....one quality being higher boiling temperature....

[nerijusj]

That looks scary Jay. Glad you didn't go down!

[ahtune69]

Did you drink something from my cooler in between session?

[kamikaze]

I think it is possible that it was boiled brake fluid....it can cool pretty quickly and you may never have it happen again. I am sure someone more expert than me can tell you about the different brake fluids....one quality being higher boiling temperature....

What are the reasons for a brake fluid boil? How to avoid it?

[butcher bergs]

Seems like that bobble didn't bother you too much.

Nice job sticking with it.

[nerijusj]

What are the reasons for a brake fluid boil? How to avoid it?

A good way to avoid a fluid boil is not to use your brakes at all

[ahtune69]

A good way to avoid a fluid boil is not to use your brakes at all

What a dick.

[nerijusj]

What a dick.

[OreoGaborio]

Nothin wrong w/ not using your brakes. I can do lap after lap hardly even scrubbing my brake pads

[butcher bergs]

What are the reasons for a brake fluid boil? How to avoid it?

Too much heat is what causes it and as the fluid gets older, that boiling point decreases.

Old brake fluid boils easier than fresh............and you know why I'm saying this.

[bmrider]

Jay,

Glad to see that you were able to keep your cool and make the turn...

As an FYI, I'm the guy you were sharing the garage with Wednesday and was leaving just as you came in after the brake "incident"...

--Brad

[OreoGaborio]

Too much heat is what causes it and as the fluid gets older, that boiling point decreases.

Old brake fluid boils easier than fresh............and you know why I'm saying this.

Not heat, but also PRESSURE. Between the heat of the friction and the PRESSURE inside the lines, that's what raises the temperature of the fluid. Once the pressure is released the fluid generally stops boiling.

[e30addict]

Not heat, but also PRESSURE. Between the heat of the friction and the PRESSURE inside the lines, that's what raises the temperature of the fluid. Once the pressure is released the fluid generally stops boiling.

Wouldn't less pressure promote boiling? Kinda like water boils at a lower temp at a higher altitude. Brake fluid isn't compressible so no heating from that

[OreoGaborio]

Correct, but.... That's because lowering the pressure just lowers the boiling temp.
Higher pressure increases temperature.... just like a pressure cooker.



Ever push down hard on the lid of a pot full of nearly boiling water? Same concept.

[e30addict]

Hmm, interesting explanation. Never thought about it like that.

[burnham]

I think you were braking too late with a good amount of lean angle. The line in was also wide. After I go over the little pink box I aim way to the left. I think you pushed the front on the brakes, probably felt like bad brakes because you were sliding. Just my 2 cents.

EDIT: I'm a dope, I was looking at the bobble at 14 seconds, not 9.

[akira700]

You could have a problem with your master cylinder.
You should check it out as you don't want that happening
again.

I would replace the fluid with some good racing stuff
I use Motul RBF600 Racing Brake Fluid.
then make sure you bleed it well.
I would never trust having someone other than yourself
working on your brakes.

[Fitz]

- Old brake fluid could definitely be a contributing factor. It has a higher percentage of water and therefore a lower boiling temperature. When it boils, it will boil at/near the caliper as that is obviously the hottest point.

- Different brake fluid has different boiling points. Usually the higher the boiling point (race fluid) tends to condense water in it easier and require bleeding more often.

- If you boiled the fluid you should have some air in the lines. The brake lever may feel spongy.

- I can't speak to bikes at all, but I would rarely if ever boil the fluid in the car at turn 1. The brakes have been cooling for the entire length of the straightaway. Turn 3 things would get a bit spongy since there was some left over heat from 1, and coming into the bowl things were still spongy. Toward the end of our sessions 3 would get real sketchy. I had to bleed the brakes after every 20 minute practice session. FWIW I've had good luck with ATE's Superblue fluid (comes in blue and gold colors for easy bleeding). Boiling point is 536 degrees F dry.

Turner motorsports in MA as well as Manchester Subaru in NH sells it. Like I said, take it for what it's worth. If your brake fluid was simply old or had not been bled in awhile, simply flushing with fresh DOT4 or 5 fluid and bleeding may get you out of the woods.

Fitz

[Evil_Weasel]

I think it is possible that it was boiled brake fluid....it can cool pretty quickly and you may never have it happen again. I am sure someone more expert than me can tell you about the different brake fluids....one quality being higher boiling temperature....

this happened to me once going into 9. not that i brake that hard for nine but still alittle brake is nice there. scary and it cost me what would have been my best finish ever.

the lever just went to mush as soon as i pulled it. thank god for rear brakes. i ran the last lap of the race alittle slower and the brakes continued to work fine.

anyway. i made the switch to Motul 600 brake fluid and it never happened again.

[Jayspeed]

I guess I'll lean more toward the boiling brake fluid now. In the beginning of the season I upgraded my lines to Galfer superbike lines and went with their HH pads. The brake fluid I got I can't remember the brand. Suzuki brand possibly. Maybe 5 trackdays (1 was rain) and 1500 street miles was too much for the fluid combined with the heat we were in? The only thing here is I don't remember losing pressure at the brake lever. When the fluid boils does the lever pull to the bar? I also didn't feel like I was doing anything abnormal either. So then I start thinking about a tire that may have slipped. These tires have gone through 4 dry trackdays and 1 300ish mile street ride. Thanks for the comments and Hey Brad, I didn't know you were in NESR.

[SVRACER01]

i say you over cooked the turn, but its all guessing even with the video.