How to change seals in a 1260 Infinity Binary, Quaternary, or Isocratic Pump without Seal Wash Option

Document created by dimsoneill Employee on Sep 3, 2020Last modified by carlos_vargas on Oct 9, 2020
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Agilent Support Insights


This Information Applies To: All Agilent 1260 Infinity Binary, Quaternary, or Isocratic Pumps without the Seal Wash Option installed.



Replacement of the pump seals in the 1260 pump head may be required in the following cases:

  • Due to a leak or some other pressure problem
  • A fail of the pressure test in Lab Advisor
  • Pump leak test in Lab Advisor suggests a problem with the pump seals

Always call your Agilent service representative to confirm this procedure is necessary.


Steps to Follow

To change the seals you have to remove the pump head, see the following article for detailed instructions: How to remove the pump head from an Agilent 1260 Infinity Binary, Quaternary or Isocratic Pump Module 

Make sure that appropriate PPE is used for the chemicals used in this process. Nitrile gloves (or equivalent) and safety glasses are recommended.

Make sure that the piston housing is tilted upward when removing it from the pump housing, to prevent the pistons falling out potentially causing piston damage.

  1. Unlock the lock screw and separate the piston housing from the pump housing. Keep the piston housing always tilted upwards to prevent the pistons from falling out of the piston housing.

  2. Remove the support rings and seal holders to reveal the piston seal underneath.
  3. Using the steel end of the insertion tool, remove the pump seals.

  4. Insert new seals into the pump housing using the PLASTIC side of the seal insertion tool. 

  5.  If the pistons seem scratched or damaged, please immediately log a service request with your local Agilent service representative.

  6. Clean each piston using isopropyl alcohol and lab wipes, then examine each piston shaft for damage or scratches.

    Do not remove the grease from the piston face and do not place the piston face down (Grease-side down) on the bench. The grease is to lubricate the face of the piston that is in contact with the pump drive, so must be kept in place to avoid wear and damage to both.

  7. Gently remove the pistons from the piston housing.

  8. Clean the inside of the pump housing, the support rings, and the seal holders with HPLC-grade Isopropyl Alcohol (IPA) and laboratory wipes.
  9. Reinstall the seal holders and then the support rings onto the pump housing.
  10. Line up the hole on the piston housing and the peg in the pump housing and connect the piston housing and the pump housing together.
  11. Gently push the pistons into the housing making sure to align the shaft of the piston through the hole in the middle of each support ring and the pump seal. Also take care not to remove the grease from the face of each piston when inserting the piston down into the piston housing.
  12. Tighten the lock screw the hold the two halves of the pump head together.

  13. The assembled pump head can now be mounted onto the pump. See Reinstalling a pump head on Agilent 1260 Infinity Binary, Quaternary or Isocratic Pump Modules for instructions on installing the pump head onto the pump module. 


Cause: Worn pump seals can shed small particles that can cause blockages and pressure issues downstream of the seals. Agilent recommends that pump seals are changed yearly, or if pump performance indicates seal wear. Indications of seal wear include leaks at the lower pump head side, unstable retention times or unstable pressure ripple.


Learn more on how to effectively troubleshoot your 1260 Infinity Pump Head please see a link to the following Agilent University course:

 HPLC-1260-2230z - Changing Pump Seals in Agilent 1260 Binary and Quaternary and Isocratic Pumps



Keywords: 1260, Binary, Quaternary, Isocratic, Replace pump seals, change pump seals, pump leaks, LC, 1260 Infinity, HPLC, pumps