Pump leak HPLC 1260 G1312b module



I am attempting to troubleshoot a leak on an Agilent 1260 G1312B binary pump. I cannot see any leaks, but my I know there is one because my leak test (pressure test) is failing with the blanking nut set at the purge valve.


Parts i replaced:
-Piston seals
-Wash seals
-Seal gaskets
-Outlet ball valve

Before and after replacing the outlet ball valve, I am getting inconsistent results when running the valve test through LabAdvisor. Sometimes it will say the ball valve is defective or the AIV results are ambiguous. Other times they will pass. 

Looking for suggestions on troubleshooting this leak I cannot solve.


  • A few things to check:


    - use the latest version of LabAdvisor (currently B.02.14 SP1)


    - thoroughly purge the entire pump with the selected solvent


    - double-check or replace the blank nut


    - using a piece of tissue, check all physical connections for leaks


    - pull the waste tube from the purge valve to check if solvent leaks to waste




    A couple of years ago, I wrote an article on problems with valve test and elasticity calibration on G1312B Rapid Resolution LC


    The elasticity calibration and the valve test have to be carried out once the pump head has been opened or the main board replaced. This sometimes can be tricky. There is not be a one-fits-all solution, but we can suggest a few things:


     - If possible, use latest FW and latest version of LabAdvisor


    - Make sure you´re in low delay volume mode, so damper and mixer bypassed


    - Make absolutely sure that the pump is very thoroughly flushed with fresh HPLC-grade water. Any trace of other solvents or the smallest air bubble inside the flow path definitely will cause the calibration to fail


    - Make sure pressure and valve test pass, before attempting to pass the EC


    - Only use correct calibration capillary assembly G1312-67500. The 2m SST capillary does not work here! The G1312-67500 capillary is fragile and cracks easily. Sometimes you cannot see the crack. Always carry at least two of them with you. Do a short test before using the capillary: With the capillary connected, pump water at 0.2, 0.4, 0.6, 0.8 and 1.0 ml/min and monitor the pressure. Pressure increase should be linear and must not exceed ~500 to 530 bar. If it does, your capillary is faulty or too long


    - Sometimes things got screwed up in the pumps memory. A forced cold restart could help


    - sometimes re-flashing the FW helps


    - it´s advisable to monitor flow and pressure during the EC. Ideally you have an Instant Pilot with you. We´ve noticed that with a bad capillary, pressure at 1ml/min can exceed 600 bar, but during Elasticity Calibration the pump is sent into flow reduction mode by LabAdvisor and does not go red, so the flow rate for EC is wrong

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