Chromatography Forum

Can someone help me with cleaning of my pump as it stopped pumping mobile phase?

Disconnect the column and see that there is no clog causing a lack of flow at the detector end of things. Assuming that you also get no flow at the pump outlet w/o a column in place, it may just need priming.

If gravity or syringe assisted feeding of eluent doesn't get it going, pull the heads and make sure that the plungers are going, that the return springs aren't broken etc.

Assuming that all is well mechanically, clean check valves, replace seals, replace plungers if they show any visible signs of wear (rings or scratches).

i tried to chnge the column and see if my column was causing the problem. but even with another column the pump doesn't seem to work.
Please suggest something else.

Make sure you're not out of mobile phase, pulling from the correct line etc, then follow the above advice (you're probably going to need some tools for this).

You didn´t run the pump without a column, like DR suggested? Maybe your second column ( or something else on-line) is plugged, maybe the injector...?

If your pupm is not able to run without column.
Check pump minimum pressure setting