Shimano GRX RX 815 Series Dealer's Manual page 13

TO ENSURE SAFETY
• If you feel no resistance when depressing the brake lever, immediately stop using the
brakes and consult a place of purchase or a distributor.
• If fluid leaks occur, immediately stop using the brakes and consult a place of purchase or
a distributor.
For installation to the bicycle, and maintenance:
• When the shifting switch is operated, the powerful 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 in
the openings of the disc brake rotor while it is moving.
• If the disc brake rotor is cracked or warped, be sure to replace the disc brake rotor with a
new one.
• If the disc brake rotor becomes worn down to a thickness of 1.5 mm or if the aluminum
surface becomes visible on one side, be sure to replace the disc brake rotor with a new
one.
• Check that the brake system has cooled down sufficiently before attempting brake
system maintenance.
• Use only SHIMANO genuine mineral oil. If other types of oil are used, it may cause
problems with brake operation, and cause vapor lock or the brake system to be unusable
• 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 hose in order to adjust the length of the brake 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 the steps in "Adding mineral oil and bleeding air".
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