I've seen similar topics, but not quite as drastic as I was seeing. I have an old Hayward 36 sq ft DE filter. I took the cartridges out to clean this weekend. After putting the filter back together, I added the DE through the skimmer. After a short while it all started pouring back into the pool through the returns. I took the cartridges back out, made sure they were all in place and didn't see any noticeable damage. I bought a new O ring for the manifold, I'll try putting that on tonight. Is there anything else I should check?
