Mileage: 9,930
Summary:
- Changed Front and Rear Brake Fluid
- Flushed ABS (using GS-911)
- Prestone DOT-4 Synthetic
- Rotated front reservoir rubber bushing
Changing the brake fluid on this bike is relatively easy. I used the brake-pump method to flush and bleed the brakes. Normally a two-person job, on this bike it was just possible for me to reach and depress the rear brake pedal while simultaneously reaching around the rear tire to open and close the bleed valve on the opposite side of the bike. The front is easier to do solo than the rear as the brake lever and single caliper are both on the right side of the bike.
Helpful Hint: Remove the screw holding the rear brake fluid reservoir to the frame and move the reservoir away from the bike, temporarily routing the hose as shown below. This is how I was able to get it to hang in free-space making it much easier to fill while also reducing the chances of spilling brake fluid onto the bike’s painted surfaces. Not shown are the rags that I used to keep any spill that might occur off of the bike.
Steps used to change the fluid on each brake:
- Flush and bleed per BMW instructions (see note at the end of this post)
- Enable the ABS pump using GS-911
- Press the brake pedal/lever for two seconds three times while the pump is on (for ten seconds).
- Flush and bleed a second time.
This job took less than an hour. Next time I think I could do it in less than 30 minutes.
Helpful Hint: You don’t need a special tool to remove the front reservoir cap, though you can buy one if you want. All you need to do is wrap a piece of string, or thin wire around the reservoir in the gap below the cap. Pull tight to compress the two locking tabs and then unscrew the black cap. Worked for me.
I’m not sure what BMW engineers were thinking when they came up with this bobble-head design for mounting the front brake reservoir. Besides being ugly, and distracting while riding, over time the constant pressure applied by the preformed hose causes the reservoir to tilt as rubber grommet looses strength where heavily compressed.
A Quick Fix for the Tilting Reservoir
After making sure the reservoir lid was tight, and protecting the bike with rags, I removed the screws holding the bracket at the mirror, and then removed the hex-head bolt holding the reservoir counterweight to the reservoir bracket. This allowed me to rotate the rubber grommet 180 degrees. I wasn’t able to rotate the grommet in place as the rubber was stuck to the bracket. Note: When I say rotate I mean around a vertical axis. I don’t mean flip from top to bottom. The later would require complete removal of the grommet from the bracket.
Rotating the rubber grommet had the intended effect of making the reservoir sit more upright as shown above. How long this will last remains to be seen; the hose is still pulling on the reservoir. The grommet (BMW #62 21 7 670 749) is available for about $3. I think I’ll add a couple to my next parts order.
The counterweight bolt was reinstalled with blue Loctite.
Note: If you plan on buying the expensive BMW DVD Service manual to learn about how to work on your ABS brake system, don’t bother. It’s not covered. The only thing I learned from the manual is that there’s a bleed valve on the front master cylinder.