4
(Pup, Lightning, AOS, and Diesel Models)
Once the system is refilled with oil, lift rear of mower until tires are
off the ground. Start engine, release parking brake, stay clear of
moving rear tires, loosen bypass bolt ½ to ¾ turns, move drive arms
forward and backward 4 to 6 times slowly. This will purge the air
from the system.
(the bypass bolt has a hole drilled through the side of the bolt head).
This valve also serves as a neutral for moving the mower without the
engine running.