Overheating brakes cause air in the lines?

[basmntdweller]

I did a track day last weekend and during one of the later sessions I think I felt the front brake go soft. It was still effective but just felt a little soft.
Tonight I was sitting at a light and grabbing a hand full of brake I could pull it nearly back to the grip. It didn't used to be that way. So, did getting the brakes hot cause the fluid to boil and create air in the lines? If that is likely the case, what bleeder system should I get?

Thanks, Matt

[SANDPSYCHO]

Brake fluid attracts moisture over time. That's why it is best to buy your fluid in small sealed cans. Once opened moisture starts to build up in the fluid. Over time it will go bad just sitting on the shelf. Running on a track you can put a ton of heat into the fluid and this accumulated moisture will start to boil in the fluid causing brake fad. Boiling water creates steam steam is a gas and gas is compressible. Change out your fluid with new fluid from a sealed can and you should have your brakes back and increase your service intervals.

I noticed I didn't answer your question so here is the answer, yes.

You don't need a bleeder system just pull in the lever a few times, hold in while you crack open the bleeder valve briefly and repeat until all the air is out.

[Jeremy Mitchell]

You don't need a bleeder but they are nice.  I have a Motion Pro one way bleeder that works very nicely for less than $15.  If you want to spend the money (usually around $120) and be able to do all your vehicle's brakes in one day then you could get the MityVac setup. 

[ZG]

Hey Matt,
Not sure where you are geographically or what the temps are there but do know that much of the USA (not the PNW of course) is setting heat records lately, could it be the rubber lines expanding so much??
 
Maybe braided lines will help, here's my setup at the link below:
http://www.zggtr.org/index.php?topic=7815.msg94273#msg94273

[SANDPSYCHO]

Air temperatures only effect the starting temp of the fluid and should have no effect on the brakes. Fluid temps on a bike running a track or even a nice canyon ride are going to be much hotter then the air temp. Braided lines do enhance brake feel and firmness over rubber line as they will expand less under equal pressure. With the short amount of rubber lines on a street bike the difference in feel is minimal if even noticeable on a street application but they do look cool.

I still say your fluid is cooked and unless your rotors are blue everything else should be fine once you replace the fluid.

[stevewfl]

Every street sport-bike and track bike I've owned with rubber lines has been ultra-squishy under extreme braking, including my C14.  Every bike except my C14 has had a brake line change that immediately resolved the prob. Doubt I change the sport-tourer's lines.

I prefer anything over galfers. Not that the others have "performed" better for me but they've physically held up better over time and haven't had the sun fade and "rust on the ends" issues all my galfers in Florida weather have had.

My favorite brand lines over the years has become these:  www.spieglerusa.com

[tonedeaf]

Brake fluid is a very non-compressible fluid and its density is largely immune to even large temperature swings, so if the fluid is not contaminated it probably is not contributing to the problem. However, if you have a significant amount of air or water in the fluid, this will produce all kinds of not good things with large temperature swings.

[ZG]

My favorite brand lines over the years has become these:  www.spieglerusa.com

+1 on Spiegler lines, the best IMO too!! 
 
I've ran nothing but them on many of bikes, unfortunetly they have no option for the Connie, trust me I tried... 

[gPink]

+1 on Spiegler lines, the best IMO too!! 
 
I've ran nothing but them on many of bikes, unfortunetly they have no option for the Connie, trust me I tried... 

Spiegler is the importer for the LSL handle bar setup which includes longer brake and clutch lines I think. Who's are those?

[basmntdweller]

I just recall one particular corner that I came down from about 135mph to 70mph fairly hard and that is where I thought I felt the lever go "soft". Not sure how old the fluid is in the bike. The bike was new when I got it one year ago this week but it was a left over '09. I don't know if they add the fluid during assembly or or it is done from the factory. I know I have never opened the system and it has felt great until that corner entry. I will try bleeding them this afternoon when I change oil and filter.

Matt

[stevewfl]

yes sir, rubber lines only go soft at times you need  MAX performance from your brakes

[gPink]

If you are going to the trouble to bleed them take the time to completely flush the system. Just bleeding them will still leave contaminated fluid in the system.

[basmntdweller]

I just checked the Spiegler link but they don't list anything newer than '07 for the Concours. Do I need to call them or is it a custom set or maybe have to order for a ZX-14?

Matt
 

[VirginiaJim]

I think you should call them if you can.  There's different lines for ABS vs non-ABS.  There is no 07 Concours.  The C14 started as an 08, but sold in the summer of 07.  I don't know if the brake lines on the ZX-14 are the same or not.  You'll need to compare part numbers between the two for your year bike.

[Conrad]

You don't need a bleeder but they are nice.  I have a Motion Pro one way bleeder that works very nicely for less than $15.  If you want to spend the money (usually around $120) and be able to do all your vehicle's brakes in one day then you could get the MityVac setup.

+1 on the Motion Pro bleeder. It makes doing the brakes and clutch a snap. You can do the whole system in about 15 mins.

[VirginiaJim]

I can do it in 14 minutes.

[Conrad]

I can do it in 15 mins and drink three beers while I'm at it.

Ha!

[gPink]

...but can you do it from the right side barefooted?

[VirginiaJim]

Such a child.  I'll drink 4 martinis (shaken not stirred), watch TV, and wear a crown.....all with one hand tied behind my back.

[VirginiaJim]

...but can you do it from the right side barefooted?

I think so.