GE AKTA avant User Manual page 313

Step
4
5
6
ÄKTA avant User Manual 29035184 AE
Action
Unscrew the purge valve by turning it counter-clockwise, and lift off the
metal ring.
Unscrew the plastic nut of the upper check valve using an adjustable wrench,
and gently lift off the upper check valve.
Unscrew the two white plastic screws located below each pump head. Pull
the plastic connectors to the sides to release the inlet manifold.
7 Maintenance
7.6 Maintenance when required
7.6.9 Clean pump head check valves
313