Shimano Ultegra R8050 Series Dealer's Manual page 11

TO ENSURE SAFETY
For Installation to the Bicycle, and Maintenance:
• When the shifting switch is operated, the motor which drives the front derailleur will operate to the shifting position without stopping, so be careful
not to get your fingers caught.
„Hydraulic disc brake
• Please make sure to keep your fingers away from the rotating disc brake rotor during installation or maintenance of the
wheel.
The disc brake rotor is sharp enough to inflict severe injury to your fingers if caught within the openings of moving disc
brake rotor.
• If the disc brake rotor is worn, cracked or warped, it should be replaced.
• If the disc brake rotor becomes worn down to a thickness of 1.5 mm or so that the aluminum surface becomes visible, be sure to replace the disc brake
rotor with a new one.
• Check that the brake components have cooled down sufficiently before attempting to adjust the brakes.
• Use only Shimano genuine mineral oil. If other types of oil are used, it may cause problems with brake operation, and cause the system to be
unuseable.
• Be sure to use only oil from a freshly-opened container, and do not re-use oil which has been drained from the bleed nipple. Old or reused oil may
contain water, which could cause vapor lock in the brake system.
• Be careful not to let water or air bubbles get into the brake system. Otherwise, vapor lock may occur. Be particularly careful when removing the cover
of the reservoir tank.
• If cutting the brake hose in order to adjust the length of the hose, or when changing over the brake hose from left to right or vice versa, be sure to
bleed the air from the hose according to steps given in "Adding Shimano genuine mineral oil and bleeding air".
• When turning the bicycle upside down or on its side, the brake system may have some air bubbles inside the reservoir tank which are still there when
the bleed nipple is closed, or which accumulate in various parts of the brake system when it is used for long periods. This disc brake system is not
designed to work with the bicycle upside down. If the bicycle is turned upside down or on its side, the air bubbles inside the reservoir tank may move
in the direction of the calipers. If the bicycle has been turned upside down or on its side, be sure to operate the brake lever a few times to check that
the brakes operate normally before riding the bicycle. If the brakes do not operate normally, adjust them according to the following procedure.
If brake does not seem to work (feels sluggish) when the lever is depressed
Set the bleed section of the brake lever so that it is parallel to the ground, and then gently depress the brake lever several times and wait for the
bubbles to return to the reservoir tank.
If the brakes still operate sluggishly, bleed the air from the brake system. (Refer to "Adding Shimano genuine mineral oil and bleeding air")
• If the quick release lever on the hub is on the same side as the disc brake rotor, they may interfere with each other, which is dangerous, so check that
they do not.
• Shimano disc brake systems are not compatible with tandem bicycles. Because tandem bicycles are heavier, the stress on the brake system increases
during brake operation. If hydraulic disc brakes are used with tandem bicycles, the oil temperature will become too high and vapor locks or ruptures
in the brake hoses may occur, and this will cause the brakes to fail.
• When installing the brake caliper using bolt fixing pins, be sure to use mounting bolts of the
appropriate length.
If not, the bolt fixing pins may not be securely fastened, and the bolts may fall out.
11
Bolt fixing pin