Kohler K-3399 Homeowner's Manual page 13

Install Fill Valve Components (cont.)
Assemble the locknut, washer, and supply nut below the tank.
Insert the refill tube with the tube restrictor into the valve.
Turn the water on.
NOTE: The level in the tank may require adjustment in order to
provide enough water for the pump to operate for the flush
duration but not too much water to overflow into the bowl. If
required, adjust the float elevation by turning the long plastic screw.
Close the circuit breaker for the toilet.
Test the toilet for proper operation.
Ensure that the tank refills to the proper level.
Install the tank cover.
Use the supplied wrench to turn the locknut to engage the hook
on the tank cover.
Kohler Co. 13 114950-5-A