Brake Bleeding - Stephen Karlan - BMW R850 Maintenance Manual

Brake Bleeding - Stephen Karlan (Dali Meeow)
R1100 and R850 yearly maintenance requires replacing (by bleeding) the brake fluid.
RECOMMENDED FLUIDS
Use only fluids from a new, never-been-opened container. The manual calls for: BMW
DOT4, Castrol Disc Brake, DOW ET 504 Shell Donax DOT 4, Hydraulan DOT 4. None
of these is a synthetic. Use the recommended fluids. Synthetics (DOT 5) are not
approved and may not be compatible with the R1100.
WARNING: Brake fluid wrecks (eats) paint immediately and must NOT come in contact
with any part of your bike!!!
Place bike on center stand for easiest access. The front brake reservoir is located on the
right handlebar and is part of the brake casting. The reservoir top measures 2-inches x
1 7/8-inches and is held on with four screws; rotate and secure the handlebar so that the
top is level. Protect the bike with a large plastic garbage bag under the front reservoir
and the right front bike area; place paper towels or rags on top of the plastic to capture
any brake fluid that escapes. The rear reservoir is a clear plastic bottle located on the
right rear of the bike; you must remove the side fairing piece to see it. When working
with the rear reservoir, the right-side plastic fairing parts must be removed and a plastic
bag may be taped so that it is held behind the reservoir and drapes down to protect the
area where fluid might leak from the rear reservoir.
WARNING: Maintain fluid in the reservoir at all times (do NOT allow air into the brake
lines)!!!
METHOD ONE:
Mityvac(r) is a hand-held vacuum pump that attaches to the bleeder valve on the caliper
and pulls brake fluid from the reservoir, through the brake line and nipple, into a plastic
line and deposits the fluid into a cup built into the tool. There is a plastic model (Part
NO. 7000) and a metal model. The plastic version is available from some WalMart
Stores for approx. $25. Metal models cost about $60 and are available from Mac Tools
(part number MV4000) and Snap-On Tools (private vendors who sell to auto repair
shops and may be found in the telephone book), and from Imparts at 1-800-325-9043,
part number 29900. Sears also sells a vacuum pump (about $35) and a brake bleeder
kit (about $10) which work well.
A Mityvac(r) vacuum pump tool is designed for bleeding brakes; read the Mityvac
information you receive with the tool. If you are not using a Mityvac or similar tool, the
difference will be explained in the paragraphs under Method Two. Both methods will
yield the same excellent result if performed properly.
Replace the fluid in the handle-bar mounted reservoir by using a turkey baster or other
device to get the old fluid out and then refill with new fluid, and do the same with the
reservoir under the seat on the right side of the bike. (Protect your paint and use
something (cup/paper/rags) to catch the drips from the turkey baster, because the
turkey baster will drip.) Fill the reservoirs with one of the recommended fluids. Now
follow the cycle of the four basic steps.
Cycle of four basic steps: (1) Create suction at the bleeding nipple which is on the
caliper, (2) Drain most of the fluid from the reservoir by opening the bleeding nipple , (3)
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