I recently changed my brake fluid on my Honda CBR600RR ... since the
procedure is just about the same for all bikes and important too
I documented it and here is the procedure, hope it helps


Manufacturers recommend changing this every one to two years and with
good reason, brake fluid is hygroscopic and absorbs moisture from the air ...
this will affect braking performance and the water content will corrode
master and slave cylinders internally over time.

Changing the brake fluid is the same procedure as bleeding the brakes only
more of it.

First you need to get the bike parked up with the master cylinder reservoir
roughly level.

I found with the 600RR that you need to have the bars turned to the
right so you can crack off the single screw holding the reservoir cap bracket
in place.





I also found by using an old dumb bell weight on the side stand as shown
and keeping the bars on full right lock it put the reservoir just about level.







Once you have undone and removed the cap bracket you can then unscrew
the plastic cap off the reservoir, always grip the reservoir when doing this so
as not to stress it's mounting ... you will see a plastic diaphragm cover,
remove this and the rubber diaphram beneath it.





Get several old rags or towels and cover your handlebars, instrument cluster,
and wheels. Brake fluid is very caustic, and will quickly ruin paint and crack
plastic if it’s spilled.

If you do spill some, even a small amount, immediately flush with copious
amounts of soapy water.


Use a NEW bottle of DOT 4 brake fluid as shown, I got mine from my
local Halfords store ... DOT 3, 4 and 5.1 are compatible, 5.0 is silicone based
and not compatible.

Keep it simple and use the recommended DOT 4.




Remove the rubber cap on the bleeder nipple, located on the caliper. Attach
a piece of clear tubing to the bleeder nipple on the caliper, and place the
other end in a waste container. An old bottle will do. Or use a one man
brake bleeder kit as I have done as shown, the tube has a simple one way
valve at the end that goes in the bottle so air cannot be drawn back in.








You need to place a spanner 8mm. over the bleed nipple first and seat it
over the hex part of the nipple then attach the rubber bleeding hose.

Open the bleeder nipple about ½ turn.

Squeeze the brake lever all the way in. DO NOT release it yet.

Close the bleeder nipple. Then release the brake lever.

Repeat these steps enough times to replace the volume of fluid in the
reservoir about two or three times.

Once you have opened the nipple if you are changing fluid as opposed to just
bleeding out some air then you can leave it open and just pump the brake
lever in and out repeatedly until all fluid is nearly expelled but not dropped
below the level of the hole in the bottom of the reservoir.

Keep a close eye on the level in the reservoir, so that it doesn’t run dry!!

If it does, it won’t hurt anything, but you’ll have introduced air into the
system that you’ll need to bleed out.
Like moisture, air in the lines will decrease the braking power. Add fluid to the
reservoir as necessary.

As shown in the picture below if you don't let the level drop below the hole in
the bottom of the reservoir you will not introduce air into the system, when
it gets this low simply fill the reservoir back up with new fluid and flush
through again.





While bleeding, observe the fluid coming out of the clear tubing. At first, you
will probably see air bubbles coming out.
Keep bleeding until bubble-free fluid is coming out.

A point to note is that you often get air introduced between the bleed tube
and nipple union so air bubbles coming out are not from the system itself, be
aware of this.

When there is no more air in the tubing, and you have clear new fluid coming
through hold the lever back against the bar and snugly close the bleeder
nipple and carefully remove the tubing, and replace the rubber cap.

Repeat the above procedure for the left hand side caliper.

Finally, top off the reservoir to the correct level and replace the cap.

Pump the brake lever until it is firm.


It is exactly the same procedure for the rear brake and as shown in the pics
you can see the position of the rear brake reservoir and the nipple and tube
in place ready for bleeding. Obviously this time you are pumping up and down
on the rear brake pedal to expel the old fluid and air. Keep pumping on the
pedal by hand until it is nearly empty but not below the level of the hole in
the bottom of the reservoir. Once you have flushed through two or three
times I did three then top up and tighten the bleed nipple with the pedal in a
down position. This is so you do not pull air back in by releasing the pedal
before you tighten the nipple.

Top up the fluid to the line and pump the pedal to get it hard again.




Note also the rubber diaphragm once you remove the cap. The rear reservoir
has two screws this time holding the cap in place.

Always grip the reservoir when undoung the caps on these so as not to
unduly stress their mount points.




Another thing to mention is cleanliness here. It was a bit breezy outside so I
did this in my garage, you do not want bits and particles blowing into your
reservoir when you have the cap off it, keep the area clean and before you
remove the cap wipe around the reservoir to remove any dust, dirt or grime.


Also do not use old bottles of opened brake fluid you may have had lying
around a while since brake fluid is hygroscopic and absorbs moisture from the
air. Buy a new bottle and use it up, I did both my bikes.


Well, hope that helps and encourages some of you to check the condition of
this vital fluid!!


Jules

 

Awesome write up!!! You can read all about my frustration here >>>> LINK

It gets really good on page 2 LOL

 

Nice writeup, thanks jules!