Replace old Jandy valve grease cups with brass plug?

[PondScum]

I have three old greasable Jandy valves installed, which have never given me any trouble (15+ years of service). A few weeks ago when a plumber came out to replace a leaking section of pipe, he commented that I should remove the grease cups and replace them with brass plugs to prevent suction leaks. Has anyone been told this before, or done this themselves? It seems like as long as they aren't giving me any problems, I should keep them. I'm guessing he also expected me to take the plugs out and put the grease fittings back in every once in a while to grease the valves, otherwise how would I maintain them?

 

[Poolsean]

The old saying applies right now...

If it ain't broke, don't fix it.

Unless the grease fitting is broken off and is already causing suction or pressure leaks, I wouldn't replace them. If you do, make sure the brass fitting is the same thread as the valve or you can strip the threads and create more of a problem.
I'd say, if you have a problem with the grease cups, replace them with the same Jandy grease cups.