I have had a pair of 2128's for about 1 1/2 years and have had no problems with o-rings or gaskets. Mine came with packets of lube which you can use to keep all the parts in good shape.
I think my eheims are about 4 years old and I have never replaced a seal between the pump and canister portions. However, I have recently ordered some of the seals that connect the tubes in the trays. They still work, but are pretty sad after 4 years.
My 2028 is making a funny cracking sound its been doing that for day or two.I took it out to clean it and still doing it.It still has a very good flow.What do I do??? ,This is a brand new filter.