BRAKE FAILURE.....Have you experienced one?

[Otto Man]

I don't think there's a universal age limit for stainless lines, but as the economy has died since 2008-09, we're seeing track bikes have a much longer service life. With that comes other maintenance that for awhile wasn't a real big consideration (servicing caliper seals, lines, etc)

Obviously even with rubber lines, that rubber isn't the actual brake line, it's still the same inner core brake line (I forget what its made out of) found in stainless lines. As a mechanic in my past career, I've definitely seen older cars/trucks have collapsed brake lines.

I think the sheer nature of the sport doesn't allow brake lines to 'age'....personally, if the brake lines are north of 10 years old, I'd be looking at replacing them. So for today, that would be a 2013 model. So let's assume you bought the bike brand new, and put stainless lines on it the day you brought it home. It's very likely those lines are just fine. It's also likely that in the span of 10 years of track riding, you've probably had a crash that damaged the lines to a certain degree (tweaked/bent/broke at the master or whatever) that warranted replacing them...so they never get a chance to truly age out.

Golden rule...if you have doubt, replace them. A set of lines is what, $130 or so? Cheap insurance. New lines, rebuild kit for your calipers and/or MC, and be on your way.

I agree that the inverted T set up (also most common for stock setups) is the easiest to route/setup. It's all I run on my bikes, the 2 line setup just annoys me.

 

[HondaGalToo]

Agree on the brake lines/pads. I replaced my brake lines after a big crash in 2012 that nearly destroyed my bike, just because. Oh jeez, the "new" lines are 11 years old. Ha.
I think I need to replace pads....soon....they are probably around the 50% mark or lower.

 

[Stickboy274]

Oh, keep your suspension fresh. Old crappy fork oil makes the forks not work proper, that will effect braking also.

 

[jsin38]

This thread is very helpful. It prompted me to take a close look at the brake system on a bike that I am bringing up to track spec.

I noticed that it took a ton of pressure on the brake lever just to keep it from pushing me down the ramp while backing it out of the truck. That was a big indicator. So I disconnected the brake lines, cracked the caliper assembly bolts, and ordered a new set of seals. Seals arrived quickly and it was time to rebuild the calipers. Left side caliper was a breeze to remove the pistons. Right side, not so much. It seems that this bike spent too much time on the sidestand in a wide variety of weather conditions and the outside pistons simply won't move. So I've ordered another set from eBay and will build a good pair of calipers with fresh seals, washers, fluid, and pads.

 

[bmart]

Nice job noticing and looking into it. I can't tell you how many times I've seen folks replace pads to (not) solve brake issues. In my experience, it is nearly always the caliper piston O-rings/seals dirty/dry/bound.

 

[meanstrk]

So sorry about your unfortunate incident and injuries “meanstrk.” I want to try to stick to “brake failure” here, but have more questions for you….
Concerning “brake fade/weak lever.” Can you explain a little more? I am assuming that you are referring to “brake fade” as when the brake fluid heats up and it takes more lever actuation to get the same braking effect.
From what I’ve read, if the brake fluid gets to it’s boiling point, create bubbles, and “poof,” no brakes.
I notice “fade” on my bike during my typical 20 minute session. I know that not all brake fluids are created equal. I’d like to hear what the endurance racer guys think/brake fluid used, etc…. Do you look at temperature rating of the fluid you use? Recomendations?

Well, I did say I experienced “failure”. As in, I pulled the lever and it came back to my knuckles. Not fade. Not weak. Just not there. It was there just fine 10 seconds before. Brake fade is typically attributed to fluid getting hot And directly contributes to a weak lever. You will usually get plenty of warning.

 

[jsin38]

Ron, do you have an indication yet as to what caused your brake failure?

After going through the caliper rebuild process last weekend, it seems to me that the piston and dust seals are not the biggest area of concern. The biggest area is the small o ring that seals the caliper halves together. This - combined with improper sequencing and torque settings of the caliper housing bolts - looks like one of those out of sight, out of mind areas that can go overlooked and cause trouble.

 

[rpm894]

Ron, do you have an indication yet as to what caused your brake failure?

After going through the caliper rebuild process last weekend, it seems to me that the piston and dust seals are not the biggest area of concern. The biggest area is the small o ring that seals the caliper halves together. This - combined with improper sequencing and torque settings of the caliper housing bolts - looks like one of those out of sight, out of mind areas that can go overlooked and cause trouble.

The Yamaha service manual for the R6 says not to split the caliper when rebuilding. Not sure if that is the general rule or the exception.

 

[Otto Man]

The Yamaha service manual for the R6 says not to split the caliper when rebuilding. Not sure if that is the general rule or the exception.

If it's a '05+ R6, good luck splitting them, because they're monoblocs. Well, I reckon you could split them easily enough...reassembling them, however...

 

[rpm894]

If it's a '05+ R6, good luck splitting them, because they're monoblocs. Well, I reckon you could split them easily enough...reassembling them, however...

Oh, you are right. Manual just says not to remove the bolts with the big star pattern on the outside. I assumed those held the caliper together but obviously not.

 

[jsin38]

Sorry, context would have been helpful in my case. I'm speaking to the Tokico calipers on the 2003 GSXR 1000. I don't think I've been lucky enough to have monoblocs on any bike yet.

 

[meanstrk]

Ron, do you have an indication yet as to what caused your brake failure?

After going through the caliper rebuild process last weekend, it seems to me that the piston and dust seals are not the biggest area of concern. The biggest area is the small o ring that seals the caliper halves together. This - combined with improper sequencing and torque settings of the caliper housing bolts - looks like one of those out of sight, out of mind areas that can go overlooked and cause trouble.

Honestly? None, other than being a completely stock system. I have been told the ABS pump is prone to cavitating and resulting in no lever, but I can’t confirm. I CAN tell you that this will NOT be a stock brake system when it is ridden again.