Just because the plunger could be removed the way you did it doesn't mean that you removed it in the proper sequence - or more important, that you replaced it in the correct sequence. I.e., it might not be step 20 of a 20-step procedure. It might be step 4.
I think it is time to do a complete teardown and find out what happened. There are photos if you search that show o-rings that seal around the six ports, and they may have become dislodged or damaged by removing the plunger. They appear to install with the entire assembly apart.
'91 MB 190E 2.3
'08 RAV4 Ltd 3.5
'83 Lazy Daze m'home 5.7