Brake Line Maintenance
11-11-2009, 12:32 PM
#1
Former Moderator
Thread Starter
Brake Line Maintenance
I saw this on bellwilliams rotor post.
It's originally from robrob, but I don't know that I really appreciated this until now.
http://robrobinette.com/cale_accident_report.htm
RIP Cale.
It's originally from robrob, but I don't know that I really appreciated this until now.
Originally Posted by robrob
Theory
With the corner worker confirming that the brake pedal was pressed (brake lights on), the lack of deceleration, the speed at impact, and the skid mark evidence, I believe the brakes failed when the right front brake line popped out of the hose end crimp connector. This is the root cause of the accident. With the brake line loose the brake pedal would have gone to the floor and Cale may have assumed his brakes had completely failed. When one of the two brake circuits fail in a car with dual diagonal brakes like the S2000, the braking available from the left front and right rear is greatly reduced and would have been insufficient to engage anti-lock braking.
Two other Honda S2000 owners reported the same exact failure with the stock brake lines. Another owner reported the same failure with aftermarket stainless steel brake lines. The hose crimp connection at the caliper seem to be a weak, failure prone part of the S2000 brake system.
With the car in fifth gear there would have been little engine braking to slow the car. Cale may have had the clutch disengaged in anticipation of the downshift for Turn 1 which would have completely removed all engine braking.
Cale initially began the turn to the right but then turned the car sharply to the left, perhaps to make the access road and its gap in the wall. It's also possible he began the turn in to the right with too much speed due to the brake failure, began to slide, over corrected and slid off the track to the left toward the access road As the car slid to the left the left front tire stayed on the access road and the other three slid through the gravel trap. The car overshot the access road and slid through grass and dirt.
The car hit a bare concrete wall on the far side of the access road, with the right side of the car approximately flush against the wall. The corner worker said the car came completely off the ground after impact and bounced away from the wall. That is consistent with what I saw when I drove by the accident site--I could see the right side of Cale's car as it was away from the wall.
Recommendations
If you plan to track your car you should replace the brake lines at regular intervals with good quality stainless steel or Kevlar brake lines. Rubber brake lines will rot and fail over time, especially when subjected to the extreme heat generated on the track. I plan to be more cautious with my brake rotors and pads. I've always run my rotors until they have small cracks and push my pads until the very end, going metal to metal several times. I had always assumed the rear rotors were bulletproof since they are solid and the rear brakes don't take as much abuse as the fronts, but that doesn't appear to be true. The rear rotors should probably be replaced at annually on frequently tracked cars..
While on the track if you are unable to make a turn and must go off track, it is usually best to go straight off into a gravel trap. Turning while going off track can lead to roll-overs or side impacts. The safety equipment in our cars is optimized for straight on impacts, especially if the airbags are still installed.
Invest in quality safety equipment. Although you can run on the track with just a stock car and a helmet, consider adding a roll bar, racing harnesses, racing seats, and a head and neck restraint. Many of us have already purchased head and neck restraints since Cale's accident.
Rob Robinette
With the corner worker confirming that the brake pedal was pressed (brake lights on), the lack of deceleration, the speed at impact, and the skid mark evidence, I believe the brakes failed when the right front brake line popped out of the hose end crimp connector. This is the root cause of the accident. With the brake line loose the brake pedal would have gone to the floor and Cale may have assumed his brakes had completely failed. When one of the two brake circuits fail in a car with dual diagonal brakes like the S2000, the braking available from the left front and right rear is greatly reduced and would have been insufficient to engage anti-lock braking.
Two other Honda S2000 owners reported the same exact failure with the stock brake lines. Another owner reported the same failure with aftermarket stainless steel brake lines. The hose crimp connection at the caliper seem to be a weak, failure prone part of the S2000 brake system.
With the car in fifth gear there would have been little engine braking to slow the car. Cale may have had the clutch disengaged in anticipation of the downshift for Turn 1 which would have completely removed all engine braking.
Cale initially began the turn to the right but then turned the car sharply to the left, perhaps to make the access road and its gap in the wall. It's also possible he began the turn in to the right with too much speed due to the brake failure, began to slide, over corrected and slid off the track to the left toward the access road As the car slid to the left the left front tire stayed on the access road and the other three slid through the gravel trap. The car overshot the access road and slid through grass and dirt.
The car hit a bare concrete wall on the far side of the access road, with the right side of the car approximately flush against the wall. The corner worker said the car came completely off the ground after impact and bounced away from the wall. That is consistent with what I saw when I drove by the accident site--I could see the right side of Cale's car as it was away from the wall.
Recommendations
If you plan to track your car you should replace the brake lines at regular intervals with good quality stainless steel or Kevlar brake lines. Rubber brake lines will rot and fail over time, especially when subjected to the extreme heat generated on the track. I plan to be more cautious with my brake rotors and pads. I've always run my rotors until they have small cracks and push my pads until the very end, going metal to metal several times. I had always assumed the rear rotors were bulletproof since they are solid and the rear brakes don't take as much abuse as the fronts, but that doesn't appear to be true. The rear rotors should probably be replaced at annually on frequently tracked cars..
While on the track if you are unable to make a turn and must go off track, it is usually best to go straight off into a gravel trap. Turning while going off track can lead to roll-overs or side impacts. The safety equipment in our cars is optimized for straight on impacts, especially if the airbags are still installed.
Invest in quality safety equipment. Although you can run on the track with just a stock car and a helmet, consider adding a roll bar, racing harnesses, racing seats, and a head and neck restraint. Many of us have already purchased head and neck restraints since Cale's accident.
Rob Robinette
RIP Cale.
11-11-2009, 12:49 PM
#2
Registered User
Considering an STi had a brake line fail this past Saturday, went home that night and replaced it, and had another failure going into T1(same place as Cale's failure whatever it may have been a day shy of exactly one year ago), yeah, brake lines shouldn't be overlooked. Rob, a couple of other S owners, and I were there for both incidents. Would be lying if I said it wasn't a little spooky.
The result of the STi's second failure: went through the gravel trap rolling twice, wheels barely touching the ground. It then hit a spot between the trap and tire wall, sprung into the air completely clearing said tire wall and neatly clipping the concrete barrier before leaving the track. The car came to rest on all four wheels on the other side. Estimated speed at time of failure: 150 mph.
The driver in question had just had a cage put in.
The result of the STi's second failure: went through the gravel trap rolling twice, wheels barely touching the ground. It then hit a spot between the trap and tire wall, sprung into the air completely clearing said tire wall and neatly clipping the concrete barrier before leaving the track. The car came to rest on all four wheels on the other side. Estimated speed at time of failure: 150 mph.
The driver in question had just had a cage put in.
11-11-2009, 01:42 PM
#5
Former Moderator
Thread Starter
It makes me want to stick with autocross.... 
I found out an old classmate of mine died this summer while climbing Mt. McKinley. Fell 2000 feet to his death. I think I'll have my brake lines replaced this Winter. I'm not a fan of tempting fate.
I found out an old classmate of mine died this summer while climbing Mt. McKinley. Fell 2000 feet to his death. I think I'll have my brake lines replaced this Winter. I'm not a fan of tempting fate.
11-13-2009, 11:34 AM
#6
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If you plan to track your car you should replace the brake lines at regular intervals with good quality stainless steel or Kevlar brake lines.
Two subaru's totalled and an S2000 with $8500 worth of damage at that event. Sort of happy I missed it.
11-13-2009, 11:42 AM
#7
Originally Posted by EK9B18,Nov 13 2009, 04:34 PM
The STI owner hasn't reported the brand of the line yet.
http://www.iwsti.com/forums/gd-members-jou...ost-1972-a.html
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11-13-2009, 11:55 AM
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Not what I'd call "big name". He hasn't reported them on Nasioc post-crash. I didn't think to check his build thread.
The Stoptech kit comes with Stoptech SS lines.
-Stoptech 6-Piston 355mm Front BBK
-Cobb SS Rear Brake Lines
-Cobb SS Rear Brake Lines
11-13-2009, 02:42 PM
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I'm skeptical. The caliper's not sitting there at 900-1500 degrees. It's not getting over 400 or so or the fluid would boil. Same thing for the lines themselves. I think most of the problem is radiated heat. Conducted heat through the rotor will kill wheel bearings. The rotor will melt tie rods from radiant heat.