Clean aperture oil 28mm 2.8 Promaster Marexar

This video shows how one can disassemble, repair, and reassemble these Promaster MC and Marexar CX MC 28mm 2.8 lenses. The problem is not always the aperture but more likely just the mechanism in the read mount that gets sticky from old grease. I have had quite a few of these and I just so happen to have two both gooey at the same time. My thought is that it seems to be a very common problem for these lenses so I hope this helps others out.
This lens is a typical 3rd party lens with multiple names and I also recall having one with the Hoya name as well. I have tried researching for a while to find out who makes it but the best I can pull up is it was possibly made by Cosina, Kiron or even Tokina. These are other’s claims but I really doubt the later two and I’m still not convinced it was a Cosina lens either. Cosina has a couple lenses similar but the closest is a macro which is again very different.
I will probably be posting a comparison between the two lenses eventually just to see the difference in build and optical performance.