cooked brake fluid? change? : Yamaha R6 Forum: R6MessageNet : YZF-R6 Forums

timbermx · 08-04-2008, 08:13 PM

My 2001 R6 (22K miles)-
checked the front/rear brake fluids, levels were right, but the fluids were brown, a lot darker than what new brake fluid looks like. Was wondering if changing the fluid would improve braking performance. I know many motocross guys change their brake fluids every season, not really sure why, and I doubt my 2001 R6's has ever been changed (I just bought it last week). What do you guys think, is it worth the time/effort?

smashweights · 08-04-2008, 10:28 PM

Quote:

Originally Posted by timbermx

My 2001 R6 (22K miles)-
checked the front/rear brake fluids, levels were right, but the fluids were brown, a lot darker than what new brake fluid looks like. Was wondering if changing the fluid would improve braking performance. I know many motocross guys change their brake fluids every season, not really sure why, and I doubt my 2001 R6's has ever been changed (I just bought it last week). What do you guys think, is it worth the time/effort?

absolutely. the effort isn't that much if you get a friend to help or a vacuum bleeder. I picked up this little magnetic reservoir with hose from AutoZone for like $5 that helped a lot. It'll take about 20-30 mins to do all 3 calipers and braking performance and response will improve quite noticeably, especially if your fluid is 7 years old, it's way overdue for a change. Plus it's cheap, just make sure you dont let the fluid level ever drop below the minimum line or you'll have to start over. Brake fluid sucks up moisture too which reduces performance over time no matter what you do.

My bike fluid probably wasn't that old but i could tell a difference. I noticed a huge difference when I did it on my Jetta though. That fluid was fuckin awful in there.

bor6sox · 08-07-2008, 11:44 AM

brake fluid is a hydraulic fluid. It will not lose its properties to stop the bike. The brownish color comes from the absorption of water. The darker the color the more water int he fluid. The problem with water in your fluid is that it will corrode the fittings. It would take a long time but it can still lead to brake failure. It is good to bleed the brakes once a year and change your lines every 4 if they are stock. If you have stainless lines they should basically last the life of the bike, but you should check their condition regularly.

timbermx · 08-07-2008, 04:15 PM

ok, so if the brownish color comes from water absorbtion in the lines, doesn't the brake fluid/water mixture have less stopping ability than pure brake fluid? Are you still recommending to change it?

smashweights · 08-07-2008, 09:36 PM

it won't totally lose it's ability to stop the bike (provided you don't develop excess or very large air bubbles) but the properties of the fluid will diminish which will degrade braking power. Water in the fluid lowers the boiling point and increases the odds of vapor formation in the brake line. Brake fluid is very hygroscopic, which is why once you open a bottle of brake fluid, you shouldn't reuse any of the fluid from it once you're done (aka: always buy in small bottles). The dark color could, but not necessarily, be from rust and or dirt particles in the fluid, which will also decrease your stopping power.

For how long you've had that fluid in there, you WILL have air bubbles. Rubber tubing does allow for some water to absorb into the fluid from the air over time. Bleed the lines and see the tiny bubbles for yourself.

smashweights · 08-12-2008, 08:45 PM

did you go through with it?

timbermx · 08-17-2008, 10:37 PM

sorry, i haven't yet, im going to do it this week Ill let you know how it goes

AwsmGy · 08-18-2008, 01:02 AM

I changed mine earlier in the season and I'm sure it was the first time it was done. I noticed a difference for sure.

MELK-MAN · 08-18-2008, 01:12 PM

roadracers change fluid every few race weekends. On the track where your using the brakes harder, lap after lap, you can really feel the change. If your bike is THAT old, dont be supprized if you see dark GOO come out of the bleeder when you go to change the fluid. It is way past time for that bike.

timbermx · 08-27-2008, 11:43 PM

Just an update:
I changed it last week, there was nothing wrong with my brakes earlier, but this made a huge difference. The fluid coming out was dark dark brown, and I flushed fully synthetic fluid DOT 4 through there, now brakes have more positive feel to them, stops quicker without as much effort.
The whole process (flushing all three calipers, replacing fluid, running to Advance Auto to pick up fluid) took about an hour and a half, and I'm no mechanic (19 year old full-time mechanical engineering college student).
Definetly recommended, cheap, easy, quick maintenance to keep your R6 in top shape!