Volvo Penta TAD1630G Workshop Manual page 95

Group 22
4
Press hard on the top of the tool and remove it. Unscrew
the seal screw by hand. The seal screw cannot be reused.
5
New seal screws (two different ones) have a pre-installed,
pre-stressed nut on the conical thread. During assembly,
you turn the nut until it releases (the screw has left-hand
threads). This provides correct torque. Screws apply to en-
gines as follows:
Screw Engine
982138 TAD1630
982145 TAD1631, TD164
Fuel system
93