Chromatography Forum

For further troubleshooting the pressure issue.

You may try to correlate the pressure drop with one pump head, e.g. drop is always if left head is pumping.

Then either its seal is worn and/or its inlet the check valve or the outlet CV of the right head is tnd isse (and vice versa).

If the CV are of catridge type, you may try to clean them by sonicating them in some nitric acid e.g. 6N., then rinse them thoroughly with water before putting them back.
But I once had a brocken CV seat, so no way to get that back to life...
So these steps may be seen as an intermediate solution e.g. until spare parts arrive.

Hollow wrote:

you may also want to have a look at

https://sciencix.com/

It looks like they provide a lot of spare parts for several, even old systems.

most likely a replacement of the plungers and seals and/or the check valves will do the job.

I went to Sciencix, and found:

https://sciencix.com/p/21267-600-610-pe ... 75/v/20934

It looks good, contacting the company to make sure it'll work with this old beast:

https://ibb.co/whvDQNzg

If so . . . should I even try to do the Performance Maintenance myself? I'm pretty good with tools and such (have never cut myself with a screwdriver), or should I "Refer to qualified service personnel"?

Thank you all for your help, you are living refutation of the supposition that the world has filled up with the rude.

R

If so . . . should I even try to do the Performance Maintenance myself? I'm pretty good with tools and such (have never cut myself with a screwdriver), or should I "Refer to qualified service personnel"?

It's not rocket science, so you may try it yourself. Maybe you'll find some "How-to" videos on the web. Maybe not for this model but Waters has some for the Alliance and UPLC. So you get the idea of how to do it.
The manual of the pump has also a section on tbe head and plunger replacement, but not too much details of the interesting tasks...
Edit: look at this Waters video: https://videos.waters.com/detail/video/ ... nd-plunger
Your pump is pretty much similar

I don't remember if the special "plunger insertion/removal tool" is necessary or just "helpful".
I only did it once during a training, long time ago...

From the technical drawing, the plunger has a strong spring sitting over the metal part and is fixed in the plunger housing with a C-ring. So the removal tool will help to press against the spring to then be able to remove the C-ring.
So you will also need a C-Ring pliers of a small width, because you have to do it on the retracted plunger quite back in its housing.

Further the "seal insertion tool" is of good help to press the new seal evenly in the pump head. Just the tool, never used the guide cylinder. for the Alliance, ghere ain't no guide at all.
For the removal of the old seal you can use just a normal screw but be careful no to screw it in too far and not scratch the pump head.

And just use plenty of pure, fresh alcohol (MeOH or IPA) to wet and clean the seals and pump head.

If unsure, maybe look for a trained service once, then watch how he/she is doing it, then next time you can do it on your own.

plungrr removal tool
https://sciencix.com/p/21074-plunger-in ... 42/v/20741

Seal insertion tool: WAT270969 (unknown for which model this part is; but you get the idea; maybe you can even 3D-print one)

Hollow!

Awesome! I'll check it out, I have to disassemble first to measure components to confirm that Sciencix has the right parts.