Link: Check Your Brakes

 

The good news is it looks like the guy was smart enough to learn from his (expensive) mistake even if he wasn't sharp enough to prevent it. Good for him.

I know I've run into a similiar problem, not ever running out of pad but coming back from a track weekend to realize one or two were thinner than I had expected. Fortunately, changing street to race pads and back for every event means I get to keep a close eye on them.

 

OwNeD! at least the guy walked away!

 

The pedal should not "sink to the floor" if the pad is worn down to the backing plate. Instead, it should act somewhat like a faded pad, as you push on the pedal and it doesn't stop as well. (Although as several people have found, the backing plates work OK as brake pads too, for a little while!)

Perhaps what really happened to this guy is that he did not have his fluid topped off. As he got very far into the piston travel, he ran out of fluid in the master cylinder. That would account for the pedal "sinking to the floor", since he would now be pumping air instead of brake fluid.

I remember hearing about this one right after it happened. T2 at Pacific is not a good place to lose your brakes. I'm going over 125 at that spot, and there is essentially no runoff.

 

IMO: when starting with brand new pads and a full reservoir there is the least amount of fluid in the system: the pistons are in as far as they go.
When the pads wear the fluid level drops.
I think all brake systems have enough fluid in the reservoir to still have fluid in the reservoir when the pad material is completely gone.
If you start out with 1/2 worn pads and a full reservoir there is even more fluid available as the pads have less to wear away and the fluid has less to replace.
Okay, if you start with an empty reservoir... you're asking for trouble.

The "ABS dump mode on ice" story.. sounds kinda strange, as if one wheel - or one side of the car - on ice makes all wheels loose brake pressure.

When the pedal sinks to the floor you have a fluid leak somewhere.
I doubt the piston popped out due to the thin pad.

 

That really sucks for that guy, at least he's okay. Too bad insurance isn't paying. I only read the original post, but it sounds like fluid level wasn't checked...

As for the ABS thing, what he may have experienced is the vehicle trying to do a "split-mu" stop which may cause braking force all around to decrease. This is where one side of the vehicle is on a surface with a lower coefficient of friction than the other side and the car attempts to slow down in a balanced, straight manner. However, I don't know if that really holds true because usually a vehicle identifies "split-mu" when one side of the vehicle's wheels lock. If the wheels weren't getting locked up, then ABS shouldn't trigger. I wouldn't call this a problem with the stability control calibration.

Regardless, a good reminder to me mindful of the brakes.

 

many brakes will pop the piston out if you run too far onto the backing plate. The s2k has a very long piston, but many bbk's the pistons are pretty short.

Seen it happen many times.

 

Parting it out ................... there's nothing left.

 

Scary pics. Luckily for him, the car took the impact very well, outside of the total cosmetic damage, the structure itself looks just fine.

I change the brake fluid before every track day and inspect everything. No excuse not to.

 

i didn't read the whole post but was he wearing any type HNR system? it reminds me of what happened to Cale and what would happened if Cale hit the tire wall instead of the bare concrete wall.

if you find yourself in a situation where you have no brakes and have time to react, what would be some of the things that you can do? down shift and risk blowing the engine or pull the ebrake?