Shimano GRX RX 815 Series Dealer's Manual page 179

MAINTENANCE
Adjusting friction
NOTICE
• Do not install the plate unit cover with a gap between the switch base and the
bottom of the plate unit. It may not seal sufficiently, which will cause the inner
mechanism to rust, potentially resulting in the adhesion of the plate.
6.
Install the plate unit cover.
Plate unit cover mounting bolt
1 - 1.5 N·m
Plate unit cover
179