Overview of Maintenance

It is necessary to perform periodic inspection of the instrument to ensure its safe use. It is possible to have these periodic inspections performed by Agilent service representatives on a contractual basis. For information regarding the maintenance inspection contract, contact your Agilent representative.

The following pages describe maintenance (simple repairs) of the pump that can be carried out without opening the main cover.

**Table:** Simple repair procedures
Procedure	Typical Frequency	Notes
Checking and Replacing the Solvent Filter	If solvent filter is blocked	Gradient performance problems, intermittent pressure fluctuations
Exchange the Passive Inlet Valve	If internally leaking	Pressure ripple unstable, run Leak Rate Test for verification
Exchange the Active Inlet Valve (AIV) or its Cartridge	If internally leaking	Pressure ripple unstable, run Leak Rate Test for verification
Exchange the Outlet Valve	If internally leaking	Pressure ripple unstable, run Leak Rate Test for verification
Exchange the Purge Valve Frit or the Purge Valve	If internally leaking	Solvent dripping out of waste outlet when valve closed
Exchange the Purge Valve Frit or the Purge Valve	If the frit shows indication of contamination or blockage	A pressure drop of > 10 bar across the frit (at a water flow of 5 mL/min with open purge valve) indicates blockage
Maintenance of a Pump Head Without Seal Wash Option	If pump performance indicates seal wear	Leaks at lower pump head side, unstable retention times, pressure ripple unstable - run Leak Rate Test for verification
Exchange pistons, see Maintenance of a Pump Head Without Seal Wash Option	If scratched	Seal life time shorter than usual - check pistons while changing the seals

21-Jun-2025