Waters ACQUITY UPLC Overview And Maintenance Manual page 120

To install the new pump head plunger:
1. Flip the pump head assembly over and then lubricate the seals with methanol.
Figure 3–107: Pump head seals
Pump-head seals
2. Carefully insert the plunger shaft into the pump head until the shaft is no longer visible.
Requirement:
Plunger shaft
Support plate
Ensure that the shaft does not make contact with the support plate.
August 8, 2016, 715005050 Rev. C
Page 120