Why is it that the brake fluid on bikes has to be changed every couple of years? No one I know ever changes the brake fluid in their cages, and no owners manual ever says it needs changing. What's different with a bike?

David

 

The manual(s) for both of our cars specify brake fluid flushes. Brake fluid is hygroscopic and absorbs water over time. In addition to hurting your stopping distance, it'll corrode the inside of your braking system.

 

In addition to Trains comment this maintenance gives you an opportunity, every two years, to use some brake cleaner spray and clean the bores of your brake pistons so they more efficiently extend and retract. Dirty bores will not retract all the way and allow your pads to continuously rub on your rotors. Taking a close look at your pads (in your hands) every two years is also a good thing to do.

Be careful and guard your paint job with a lot of shop rags before you change the fluid in the front reservoir. Brake fluid can damage paint.

 

Changed mine a couple months ago, old fluid was nasty looking. Brakes seemed liked they worked better after changing fluid also.

 

I just flushed mine. Cost is minimal if you do the work yourself.

 

Yep. The maintenance schedule in every owner's manual I have specifies brake fluid change every two years independent of mileage.

 

Thanks, guys! A couple other questions. When I'm pumping the new fluid through and pushing out the old, I need to keep an eye on fluid level. Do I need to install and tighten the master cylinder lid each time I fill the reservoir up, or can I leave the MC lid off and just add as needed? Is a new lid gasket needed or can I reuse the old one?.

David

 

Leave it off.

 

You leave the lid off, you have to keep adding fluid as you drain out the old. If you let the Master Cylinder run dry, you'll get air in the system and have to start all over again.

My bike is three years old and I re-used the gasket, but probably not a bad idea to replace with a new one.

Get yourself one of these, makes the job very easy.


If you can get a helper to add fluid as you drain the old, makes things easier also.

Buy a Service Manual for your bike, will save lots of money and headache in the long run.

 

I prefer the simple route and installed speed bleeders. No extra help necessary with these things. You can do the job yourself. They disallow air from being sucked back into the nipple on the caliper when you let go of the lever. They eliminate the need to loosen-squeeze-tighten-release-fill-loosen-squeeze-tighten-release-fill, etc.,etc.

With the speed bleeders, all you do is loosen them 1/4 of a turn, then start pumping brake fluid through your reservoir until it turns clear down at the caliper nipple. Turn a quarter turn to cut them off and you are done. You will need three speed bleeders for a touring bike if you go this route.

http://www.speedbleeder.com/