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Brembo Technical Notes
A.
All brembo braking products use a 1.0mm x 10.0mm thread pitch
for hydraulic fittings. (Honda, ISR, Kawasaki and Yamaha use 1.25mm
x 10.0 thread pitch for their fittings, Suzuki use 1.0mm x 10.0mm).
Be aware of this when using brembo components with your machine.
Always use fresh copper or aluminum sealing washers when installing
new or reinstalling old components.
B. All brembo braking
products use natural-rubber base seals, and therefore are INCOMPATIBLE
with DOT-5 SILICONE-based brake fluids. DOT- 5 SILICONE-based
fluids react with natural-rubber seals to swell them WHICH CAN
CAUSE SEVERE PISTON RETRACTION PROBLEMS. There is no cure for
problems caused by DOT- 5 use other than complete seals replacement
- USE ONLY DOT-3/4 NON-SILICONE TYPE FLUIDS such as CASTROLTM
'LMA' in your brembo components.(Yes, we know the cap on the rectangular
master cylinders says "DOT 3 - 5 Fluids"-BUT PLEASE
NOTE: Silicone DOT- 5 fluids are NOT generally in use in Europe,
but Glycol-based "DOT-5.1" fluids ARE. Hence, the "DOT-5"
cap designation). For best braking performance, we recommend changing
brake fluid twice a year. If the machine is to be stored in a
damp environment (over the winter, say), we recommend installing
fresh fluid before and after the storage period. At minimum service
levels, glycol brake fluids MUST be completely changed at intervals
not to exceed a period of 18 months.
C. Brembo-recommended brake
bleeding procedures:
1. Fill the master cylinder reservoir with fresh, specified brake
fluid from a sealed container. Operate the master cylinder lever
SLOWLY several times to fill the brake circuits and begin to expel
air from them.
2. Connect a transparent plastic tube (of appropriate
bore for a leakproof fit) to the caliper bleed valve, placing
the free end in a brake-fluid-proof container. Position the bleed
tube so that it rises above the bleed valve for a few inches (to
allow a fluid head above the bleed valve exit) before descending
into the container.
3. Operate the brake lever 3 - 4 times, keeping it
pulled in on the last stroke. Loosen the caliper bleed valve enough
to allow fluid and purged air (seen as bubbles in the fluid) to
enter the attached tube. Close the bleed valve. Repeat this operation
several times while maintaining a sufficient fluid level in the
master cylinder reservoir. With each cycle of bleeding, the lever
should meet with more resistance, indicating that the air is being
removed from the system (there should also be progressively fewer
bubbles in the purged fluid in the tube). If conditions are ideal,
satisfactory lever resistance should be attained at the point
no more bubbles are observable in the purged fluid in the tube.
4. Occasionally, a system will still have "spongy"
lever even though no more air can be found in the purged fluid.
This indicates air is still trapped in some part or parts of the
circuit, and must be removed. The following methods will help
to free the trapped air and complete the bleeding process:
(a) Making sure the reservoir is filled and capped,
lean the machine so the reservoir is positioned above the master
cylinder outlet, then give the lever several short, quick strokes.
This gives the residual air a less- interrupted upwards path towards
the reservoir, and out of the line. Return the machine to the
upright position, rap the calipers sharply with a plastic hammer
or screwdriver handle, manipulate the flex lines and repeat. If
this doesn't quite correct the problem, let the machine sit overnight
and repeat the next day. In most cases, this should give an air-free
final bleed. Be sure the reservoir is filled to the correct level
after final bleeding.
(b) In the case of master cylinders mounted on clip-on
bars with a steep angle, it may be difficult to lean the machine
sufficiently to position the reservoir above the master cylinder
outlet. In this case it will be necessary to bleed the fitting
at the high point (i.e. the master cylinder outlet). If your machine
is fitted with a bleed-type banjo bolt (see FD ), this is a simple
process of fitting the plastic tube and bleeding in the normal
manner. If not, this can still be accomplished by bleeding the
standard fitting with some basic precautions: (1) Be sure the
sealing washers for the fitting are fresh (2) Position an absorbent
rag or towel around the fitting to prevent expelled brake fluid
from contacting painted finishes (3) Pull the brembo master cylinder
lever in fully and hold (4) Loosen the fitting just enough to
allow fluid (containing any trapped air) to escape onto the rag
(5) Retighten fitting, release lever, remove rag, check brake
action (6) Recheck reservoir for correct level and fill if necessary.
(As many machines now use clip-on master-cylinder
fitment, this procedure for bleeding the high point of the system
can be useful in firming lever response on machines which seem
to have had a "soft" lever from new. Although an initial
system setup bleed may yield nothing but fluid at the calipers,
unbled air at a high point outlet of a master cylinder is often
overlooked if for no other reason than minute residual air bubbles
will, with time and use, loosen and rise, coalescing at the high
point into a large bubble that will defy any attempt to bleed
it out at the calipers. Since fluid from the reservoir will simply
flow underneath an air bubble at a high point during a bleeding
process, a resultant "spongy" lever is often incorrectly
blamed on the braking components rather than an incomplete bleeding
procedure). (c) In particularly troublesome cases another method
may be used in conjunction with method (b)- (1) Remove caliper
from disc (2) Fit bleed tube, container and check reservoir level
as in C1 & C2 (3) Open bleed valve (4) Slowly push the caliper
pistons their fully retracted positions (5) Close the bleed valve
(6) Refit caliper to disc (7) Operate master cylinder to extend
pads to disc (8) Remove caliper from disc (9) Remove master cylinder
reservoir cap (10) slowly push the caliper pistons to their fully
retracted positions, taking care that the fluid in the master
cylinder reservoir does not overflow onto a painted surface (11)
Refit caliper to disc (12) bleed master cylinder high point as
in method C4(b) (13) Check brake action, adjust reservoir level
and recap. (If the wheel/disc assembly is removed to perform this
method, be sure that a plate or shim of the same thickness of
the disc is inserted in place of the disc into the caliper not
being bled-this is necessary to prevent accidental loss of pistons
and fluid during this process).
Things to remember when
bleeding brakes:
Air tends to rise through brake fluid and lodge
at high points in the brake system. Anything that can be done
to ease the upward travel of air to the fluid reservoir in a hydraulic
system will make a complete bleeding of the brakes that much easier.
Avoid overfilling the master cylinder reservoir.
Too much fluid will result in brake drag or even brake lock.
Glycol-based brake fluids are highly damaging to
painted surfaces and certain plastics. Extreme care should be
taken to avoid spillage of brake fluid when working on a brake
system. Any spills should be blotted up immediately flushed with
large amounts of water, blotted again, and flushed again.
Used brake fluid (even clean, fresh fluid pumped
through a new system to bring it up) should NEVER be reused.
MAKE SURE the master cylinder lever has at least
0.1mm freeplay between the lever cam or pushrod and the piston,
i.e. - be positive that the piston is FULLY returned when the
lever is released. EVEN SLIGHT ENGAGEMENT OF THE PISTON CAN RESULT
IN BRAKE DRAG AND/OR LOCKUP!!!
D. At every brake
pad change we recommend checking the thickness of your brembo
brake rotor against the minimum thickness found stamped on the
edge or mounting flange-this will let you know how close the disc
is to the end of its service life and allow you to take steps
to maintain your system in top order. Operating any brake disc
below its minimum thickness can result in total brake system failure.
Be sure to perform this vital inspection no matter whose brake
system you are using. Brake pads themselves should never be used
with friction material less than 0.8mm in thickness for the same
reason.
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