Chromatography Forum

We have a leakage problem with our Shimadzu LC-10AD pump.
we have changed the diaphragm, and plunger seal but it still leaks from the check valve on of the pumps.

I have to mention that this pump did not come with a "thin plate" and "plastic sheet" as indicated in the manual.

the other pump doesnt have these two and it works fine.

if there anything else i can do to fix this issue? we have tried almost all options but cant fix this leak.

thanks for your input

Optimize Technologies carries a pretty complete line of parts, including cartridge check valve replacement systems that I have had good luck with in the past.

thank you for your reply. but that doesn really solve/answer my problem.

where is optimize technologies? website? tel no?

I am not sure I understand where you have your leak but I will put in my two cents worth anyway.
Does the eluent leak out of or through the checkvalve?
If it leaks through the checkvalve (you loose pressure) most likely the problem could be solved by sonicating the valve in 50/50 methanol/water.
If you have leakage actually comming out (so you se it) from the inlet or outlet from the check valve likely the thredding is damaged and you need to replace the valve or you have the wrong seating distance (tubing sticking out from the ferule on the tubing) or the wrong ferule.

thank you for your reply. but that doesn really solve/answer my problem.

where is optimize technologies? website? tel no?

http://www.optimizetech.com/

I am not sure I understand where you have your leak but I will put in my two cents worth anyway.
Does the eluent leak out of or through the checkvalve?
If it leaks through the checkvalve (you loose pressure) most likely the problem could be solved by sonicating the valve in 50/50 methanol/water.
If you have leakage actually comming out (so you se it) from the inlet or outlet from the check valve likely the thredding is damaged and you need to replace the valve or you have the wrong seating distance (tubing sticking out from the ferule on the tubing) or the wrong ferule.

the leak is actually coming from the around INlet check valve.
the threads are smooth (so I know they are not compromised).
as far as tubing not seated right, that maybe. we might have to just order a new INlet check valve and see what happens.

Dear,
We also have the Shimadzu LC, with this pump model.
The in- and out- check valves must be tightened sufficiently (on the working pump head).
I believe that you should clean both check valves (with sonicating), then reinstall. And don't over-tighten the valves.

Do you have an automatic washing system (for washing back seals)? Check if this part is leaking.

alfred

Our systems have plastic tubing and one-piece nut/ferrules going to the inlet check valves. If yours is the same, have you tried switching the inlet check valve from the right pump head to the left (and vice versa) to see if the problem moves to the other pump head?