Yamaha Starbike Forum banner

1 - 20 of 31 Posts

·
Registered
Joined
·
621 Posts
The manuals all say every two years, but I'm going into my third year with my original brake fluid, and I'm not really thinking about changing it this year. I haven't felt my brakes getting squishy so far. In my non-legally-binding opinion, I'd say "when the brakes start to feel squishy."

When my girlfriend got her 650 last year, one of the first things I did was change the brake fluid, and it firmed up the brakes a lot, but I'm guessing maybe the fluid in that one hadn't been changed since the bike was new in '02.
 

·
Banned
Joined
·
4,088 Posts
how often should you replace your brake fluid?
I PM'd another member with the answer. :D:D











My understanding is every 2 years is good and it is what I do. From what I've been told and from what I've read (not in the manual of course which just tells you "how often"), is that brake fluid degrades more so over time due to water absorbsion and not from performing it's hydraulic functions. Not that water can't be an effective hydraulic fluid (because it can) but it likes to become rancid and causes corrosion to innards of our brake systems. The big mystery to me is how moisture is allowed to interact with the fluid inside our brake systems, but apparently it does.
 

·
Banned
Joined
·
4,088 Posts
Water get in it from the reservoir because it is open to the atmosphere. Ever time you use your brakes the fluid is move back and forth. Air in Air out- Fluid up Fluid down.
Well I'll be darned, I thought there was a diaphram between the atmosphere and the fluid. I get caught in the rain alot, maybe thats why my brake fluid level is always good :D:D
 

·
Banned
Joined
·
4,088 Posts
I suppose there is some kind of vent outside the diaphram so maybe over time the diaphram allows moisture to pass thru it. Otherwise the amount of moisture in there, from day 1 is from Japan (so to speak), and would never get worse. Once every 2 years is cheap and easy I suppose.
 

·
Registered
Joined
·
2,904 Posts

·
Registered
Joined
·
1,452 Posts
Well said all of you. Do what the book states for godsake, it's you brake system.I don't think a pint of dot 4 will break anybodies pocket book. Be on the safe side and flush out the fluid.It's not a good feeling when your brakes fade away on a panic stop. Safety first guys and gals.
 

·
Administrator
Joined
·
13,683 Posts
Discussion Starter #10
I don't think a pint of dot 4 will break anybodies pocket book. Be on the safe side and flush out the fluid.It's not a good feeling when your brakes fade away on a panic stop.
i don't think it's an issue of price, but of procedure. i'm gonna have to look up how to do it and it sounds like it could be more complicated than changing your oil. my bike just hit the 3 year mark and and 25K miles and i'm looking to do all the preventative maintenance on it right now. still don't know if i want to trust myself to learn how to check valve clearance.
 

·
Banned
Joined
·
4,088 Posts
i don't think it's an issue of price, but of procedure. i'm gonna have to look up how to do it and it sounds like it could be more complicated than changing your oil. my bike just hit the 3 year mark and and 25K miles and i'm looking to do all the preventative maintenance on it right now. still don't know if i want to trust myself to learn how to check valve clearance.
Brake fluid change is indeed a bigger PITA as compared to doing an oil change. Much easier with finding a helper. Helper is needed after you drain and flush the old fluid. After that I find it to be a slow arduous process to begin filling the master cylinder until it starts to come out the bleeders down at the calipers (dual front disks will more than double your fun). Then after you get fluid to emerge from the bleeders comes the air purge which is very exciting. Replace the cover onto the master cylinder, re-open the bleeders while your helper performs a sloooooow steady squeeze of the brake lever, close both bleeders before the helper releases the brake lever, release brake lever, open bleeders and repeat about a million times until the "spongy feeling" is gone. Keep in mind while this is on-going to keep another eye on the brake fluid level because you will have to add more fluid, probably more than once, during the ordeal.

OR

$chedule a $ervice vi$it and go look at the new toy$ in the $howroom while a wrench doe$ it for you.
 

·
Registered
Joined
·
621 Posts
Here's a (partial) repost of something from a different thread. There's a much easier way to change brake fluid without all that bleeding. In short, don't put the air in the system to begin with.

Instead of draining the system, then adding to an empty master cylinder (which is what lets the air in to begin with), connect your bleed hose and make sure the waste end is submerged in a little bit of brake fluid in your waste container. Open the master cylinder and the bleed screw, and squeeze the brake lever until the fluid goes down some, but not enough to empty the master cylinder. Top the master cylinder off and repeat until new brake fluid makes its way out the bleed screw.
 

·
Registered
Joined
·
30 Posts
Why not just do a gravity bleed? Simply open the master cyl, top off with new brake fluid, open the bleed screws (can connect hoses to direct drain away from the bike if you like) and watch and wait. Its slow but you stand no chance of mistakenly introducing air into the system. Gravity will pull the fluid down through the hoses and out the bleed screws all you have to do is watch and keep topping off the master cyl to keep it from running dry. In a short while you will see new fluid coming from the callipers.
 

·
Registered
Joined
·
1,880 Posts
Why not just do a gravity bleed? Simply open the master cyl, top off with new brake fluid, open the bleed screws (can connect hoses to direct drain away from the bike if you like) and watch and wait. Its slow but you stand no chance of mistakenly introducing air into the system. Gravity will pull the fluid down through the hoses and out the bleed screws all you have to do is watch and keep topping off the master cyl to keep it from running dry. In a short while you will see new fluid coming from the callipers.[/QUOTE

Sounds too easy, but believe it or not folks, it does work:D Done it myself. Thanks Chris, you done good!:)
 

·
Registered
Joined
·
30 Posts
Will the old brake fluid actually look dirty so you can tell the difference between the new brake fluid coming out?

Sent from my PC36100 using Motorcycle.com App
depending on the condition of the fluid yes. Typically old fluid has more of a brown look and new is more clear. you should be able to see the difference when you look in the bottle of new and compare with whats in the master cyl.
 

·
Banned
Joined
·
4,088 Posts
So the old saying about old dogs and new tricks is not so true afterall, I'm loving this method! Thanks Chris T.
HIP HIP HOORAY, HIP HIP HOORAY, HIP HIP HOORAY
 
1 - 20 of 31 Posts
Top