HEXHEAD Tech - R1200R - '07-09 Brake Fluid Flush

[deilenberger]

FRONT RESERVOIR CATCHES

This photo shows the two catches that keep the reservoir cap from unscrewing.

These are part of a plastic retainer that keys into the reservoir housing, and also keeps the rubber bellows assembly in position.

[deilenberger]

REMOVING THE BELLOWS AND DRAINING THE OLD BRAKE FLUID

This photo shows removing the retaining catch assembly and the rubber bellows. Make a note of where the fluid level is after the bellows is out of the way. This is the level you want the new fluid to be at after doing the fluid flush.* After removing the bellows assembly - clean and dry it with a lint-free cloth, and set it aside somewhere safe.

* = The brake fluid level will drop as your pads wear. This is normal. If you fill the fluid to the max position with worn pads - the fluid will then overflow when new pads are fitted. That's not a good thing since it will likely attack the paint on your tank.

As with the rear brake - you should remove as much of the old fluid from the reservoir as you can (the purloined turkey-baster comes to use again..) and then fill it with fresh fluid, being careful not to expose the hole going down into the master-cylinder to air (which keeps air out of the system, preventing this becoming a brake-bleed session.)

WARNING: Notice that a towel is now being used to protect the tank and any other painted parts from errant drops of brake fluid. It seems almost impossible to pour fluid from a brake-fluid bottle without some dripping.

[deilenberger]

FLUSHING THE FRONT BRAKE CIRCUIT

Before doing the flush on the front brake caliper - remove the caliper from the fork leg (one at a time) - and retract the pads and pistons (as was done on the rear caliper) with the bleeder open and bleed hose connected. This way the gunky fluid from the pistons goes out the bleeder rather than being forced up into the system. Once the pads are retracted, use something of suitable size to block the pads from closing up again while the bleeding takes place. (I happened to have a nice aluminum block the perfect size - some creativity is allowed in finding the right "block".)

NOTE: As the photo below shows (red circle), I took this opportunity to replace the stock bleed nipples with "SpeedBleeder" nipples. These are a US made product that is a bleed nipple with a check valve internal to the nipple. What this means is - bleeding or flushing the brakes can be done much easier than with the stock nipple.

SpeedBleeders are available at many auto-supply stores, and on-line. I bought these via Ebay at a cost of about $7.00 each. The sizes needed are (2x) M7 x 1.0 [front - PN SB7100S] and (1x) M6 x 1.0 [rear - PN SB6100]. (Ebay vendor is: kz10cubed - highly recommended, very fast delivery and communications) or they can be ordered right from the company: http://www.speedbleeder.com/ The SpeedBleeders are made from US sized bar stock - so you'll need some small SAE wrenches to use them (in the case of the front - a 3/16" box wrench.)

Now we can proceed to flushing the front caliper.. I'll describe both the steps for the stock nipple, and the steps with a SpeedBleeder.

STOCK BLEEDER:

1. Crack open bleeder 1/8th turn
2. Depress brake lever ~2" and hold it
3. Close bleeder gently
4. Release brake lever (allowing master cylinder to refill from reservoir.)
5. REPEAT 1-4 until clear fluid is coming out the bleeder.
6. Gently close bleeder

OR

SPEED BLEEDER:

1. Crack open bleeder 1/8 turn
2. Pump brake lever until clear fluid is coming out (make sure reservoir doesn't run dry)
3. Gently close bleeder

Once done with the right side, remount the caliper to the fork leg with the T45 bolts, torqued to 30nM (~22ft/lbs). Then pump the front brake back up to seat the pads on the rotor. Next repeat the process on the left side caliper.

WARNING: For bikes with ABS - exercise care when replacing the left side caliper on the fork leg. It's possible to capture the ABS sensor wiring in the caliper. This would be a bad thing to do.

As usual - be careful not to let the fluid level in the reservoir drop below the hole in the bottom that feeds the master cylinder.

[deilenberger]

REFILLING THE RESERVOIR

Remember the level the old fluid was at before we started the flush? That's the level to shoot for with the new fluid when you're done.

If you're replacing pads at the same time as the fluid flush - you should then fill the reservoir to the MAX line which is right at the bottom of the cap threads after installing the new pads and seating them on the rotors.

[deilenberger]

REINSTALLING THE CATCH/BELLOWS ASSEMBLY

Now it's just a matter of replacing the now clean/dry bellows assembly and the catch:

[deilenberger]

FINI

Finally replace the reservoir cap.

All done - make certain you've pumped up the brakes, front and rear, before taking the bike out for your celebratory ride!

NOTE: Please dispose of the old brake fluid in an environmentally safe manner. In general - it can be mixed with old engine oil for recycling. For the location of a recycling center near you see: http://earth911.com/