It's here!! By popular demand! Leslie and Arianrhod show you how easy it is to do your own ABS brake bleed on the '02 BMW R1150RT!

A little background: Leslie bought Marty's 1150RT back in April with 30K on it and named her "Arianrhod" after the Celtic Moon Goddess whose name literally means "Silver Wheel". She has proceeded to become quite the rider and has even recently earned the title "Mama Hoon"! smile Despite still being almost a novice rider (only about two years), she's put well over 16,000 miles on Arianrhod since Easter! The RT just begs to be ridden far, wide, and hard--but putting on those kinds of miles sure can make those expensive services come around quickly! Arianrhod is about two years old now and it's time to bleed the Wheel Circuits and the Control Circuits on the ABS integral linked brakes, as well as the hydraulic clutch.

I had bled the ABS Wheel Circuits last week on my '03 and she observed the procedure closely. She said she wanted to do her own full bi-annual/major service this time. She'd seen it done once before and we have the shop manual from Motobins in the UK to follow along with all the required steps. For the record--I didn't even help (I think I helped break one or two bolts loose)--my hands stayed clean enough to take these pictures. Keep in mind, Leslie went to school in the days when "girls" didn't take auto shop--her only option at that time was Home Economics. She also didn't grow up around a mechanic's shop or hand tools, and is totally taking to this new-found hobby with some trepidation, but a determination that is MOST impressive!

So all you guys and gals out there who have been intimidated by the thought of doing your own services, or consider yourselves not to be mechanically inclined: sign up for the next Tech Daze near you! If there isn't one--start your own! If you schedule it, they will come! But if you've got an 1150 and would like to see what's involved in servicing those mysterious linked, power-assisted brakes (you know, the ones where, if you dare to touch them yourself will set a pox upon your house for generations to come--as well as void your warranty! grin ), set a spell, pour yourself a cold one, and let Les walk you through the fairly simple steps to saving yourself thousands of dollars and keeping your R1150RT running in tip-top shape! cool

This will hopefully be the first in a series of photo-documented service walk-throughs. She also just did her tranny fluids, final drive fluids, and fuel filter change. We forgot to photograph the rest of the annual and major service: oil and oil filter change, valve adjust, TB synch, throttle cable and fast idle cable freeplay adjustment, etc. Maybe next month when we get back from the UnRally! smile

I had made one of rosemab's funnel-thingy's (which he once christened the "Mini-Stan" smile ) from info on this DB. It works like a champ and MAJOR kudos to everyone who contributed to this fascinating discussion! I had ordered a few SpeedBleeders for my bike, but the sizing info on their page is incorrect for the '02's on. Still, I would HIGHLY recommend them! They take an extra step to install the first time, but then--oh, the simplicity of it all! The "Mini-Stan", a syringe with some tubing (and an old stock bleed screw stuck in the end!), the SB's, in addition to the TOTALLY slick catch bag with silicone hose SpeedBleeder sells, makes it an amazingly easy procedure! You should definitely have the BMW shop manual handy and read through all the procedures and cautions before you start! Motobins in the UK sells it on CD for a great price (and they have a great catalogue, too! smile ). I printed out the pages and put them in plastic sheet protectors (back to back! smile ) and placed them all in a three-ring binder. If you're uncomfortable with any of the steps, get help before you screw something up irrepairably! We offer this tutorial merely as a service to the members--don't send your lawyers to come banging on my door cause you got yourself in over your head. laugh RTFM! rofl

Here are the main specialized tools of the trade you'll need to make the job easier:

The Mini-Stan, a 60cc syringe with 8" or so of 1/4" I.D. X 3/8" O.D. vinyl tubing and the stock 8mmX 1.25 bleed screw stuck in the end to keep it from dripping, and the catchment bag SpeedBleeder sells to keep everything neat and clean.

And here is a fuzzy detail shot of the special order ABS "Bleed Plug" Part# 90886342541, Desc: "TOP". You can order one from Marin BMW perhaps you've heard the name S. Cary Littell, Jr.? If you're reading this you owe him more than you'll ever know. I bought a rubber washer (that I had to cut the middle out of to make fit) to seal it well, since it will be holding brake fluid above the level of the reservoir.

I came home from work one morning to find Arianrhod sitting stark naked in the garage! Leslie had already pulled all the Tupperware, glove box, air intakes and even the tank!

The BMW R1150RT uses a new concept in ABS brake technology that is very different from standard brakes, which you may or may not already be familiar with. Without getting into the fact that BMW has not felt the need to allow us the ability to unlink the two brakes--instead of a Master Cylinder mounted on/near the hand and foot controls that actuates the brake caliper(s) directly, the 1150 uses two separate circuits: a control circuit actuated by the hand and foot controls which controls the servo-assisted wheel circuit (under the gas tank) which then powers the calipers at the wheels. This means that the normal reservoirs you might be used to seeing, and the caliper(s) at the wheels are not really directly connected at all! eek The wheel circuits are bled every year (they are under the most pressure) and the control circuits are only bled every two years.

The reservoirs for the wheel circuits are on the left (port) side of the main ABS housing under the tank. The front wheel circuit reservoir is fore, and the rear wheel circuit is aft. The bleed screws for these reservoirs are on the calipers at the wheels themselves. On the right (starboard) side of the main ABS housing are the six bleed screws for the control circuits front and rear. The reservoirs for these control circuit bleed screws are at the right hand grip (in front of the hand brake lever) and at the right side rear (under the black plastic panel).

Here are two shots trying to show the six control circuit bleed screws (with the dust caps removed for clarity) on the starboard side of the main ABS housing under the tank:

See the fuel filter replacement walk-through (coming soon! laugh ) for details on how to remove the tank.

Remember, that since the brakes are permanently linked, all the calipers must be either properly installed (with pads!), or removed and securely shimmed! If you switch the bike on and touch either control, the pistons will otherwise be slammed together! Open the front wheel circuit reservoir with a 19mm wrench and draw off the old brake fluid. (The rear reservoir is shown here, but the front reservoir is immediately to the fore)

Remove the front brake calipers, push the pistons ALL the way out, and shim them securely in

If your front pads are worn, your shims will hit the raised nubs at the ends and bottom of the calipers and they will not be able to keep the pistons fully retracted. If this is the case, place additional shims on the outside of each pair of shims, between the shims and the pads on each side to keep the pistons fully retracted when actuating the servo. Two shots for clarification:

After pushing the pistons all the way out, the brake fluid in the lines will be forced back into the reservoir. This is why you draw off the fluid first--to prevent an overflow. Now draw off this additional fluid in the same way as before, then attach the Mini-Stan and fill the reservoir with fresh DOT4 fluid FROM A CLOSED CONTAINER. When you break the seal on a bottle of brake fluid, the clock starts ticking. You should replace the fluid every year (regardless of miles), so why not start with good, uncontaminated stuff? Here's a picture of the Mini-Stan installed in the front reservoir and filled with fresh DOT4.

Instead of needing a power assisted brake bleeding device like the Mighty-Vac, BMW has thoughtfully provided you with a built-in, servo-assisted, bike powered brake fluid pump! Be vary careful when squeezing the controls! If you pump away like normal brakes, you will empty the reservoir in no time, cavitate the pump, and contaminate the system with air! Remember, air does not compress the way brake fluid does--you need that compressive strength to stop you--air in your brake system is NOT your friend! frown

Switch on the bike and wait for the ABS to perform its initialization and self-check. Crack the bleed screw 1/4 to 1/2 turn and bleed the left side slowly until the fluid coming out is nice and clean, clear in color, free of bubbles, and always keep the Mini-Stan at least partially full of fluid--then do the right side the same way. Remember, if you're doing the bleed with the stock bleed screws, and especially if you're not using the silicone hose, you must close the bleed screw before releasing the lever to prevent air from being drawn back into the brake line (which the SpeedBleeders' ball check valve automatically prevents!). Air can be sucked back in around the threads as well when fluid is not being forced out through the bleed screw, when you release the hand control. When you're done with the right side, bleed enough fluid down just until the fluid disappears from the stem of the funnel-thingy. Remove the funnel, and assure that the fluid level is just below the "MAX" mark. It will drop a bit when the caliper pistons return to their previous position.

Remember, if you are installing SpeedBleeders: since the system is not closed, and the calipers are below the level of the reservoir, when you remove the stock bleed screw, the brake fluid will leak out. Just wrap paper towels around the calipers, quickly swap the stock screw for the SB--being careful to not cross-thread it in the process--and carefully wipe off the spilled brake fluid. The first few threads on the SpeedBleeders do not have any thread sealant on them for this reason. Tighten the SB down carefully, feeling for the difference between thread sealant compound resistance and over-torqueing/stripped resistance. The bleed screws only call for 7Nm of torque to fully seat.

After the front calipers are bled, remove the shims and re-install the calipers. Switch the bike on again, wait for the ABS to cycle and then bed in the pads against the rotors. Depending on the wear on the pads, if the fluid drops significantly in the reservoir, top it off to the "MAX" mark again, then close the reservoir cap. Once the front calipers are completely finished, the back is done the same way.

Stay tuned for scenes from our next show: Bleeding the ABS Control Circuit on the R1150RT! cool

Cool_Jamie "KMG_365"
"Dry-Town" Crew, San Diego
"Maynard" "the Krebs Cycle" '03 R1150RT, black