When Replacing Suction Pipe:

WARNING: This page is about a different car, the 2002 Volvo C70, 2001 Volvo C70, 2000 Volvo C70, 1999 Volvo C70, and 1998 Volvo C70. However, it is still accessible from the selected car via links, so may be relevant.

first read section Before Starting Work On the Receiver/Drier Or Suction Pipe
fill the new suction pipe with new oil. Also see Oil Air Conditioning (A/C) System, Filling
install the suction pipe onto the receiver/dryer. Tighten to: 30 Nm.
NOTE: Install the suction pipe in the same position noted when it was removed.