98 Taurus transmission gasket leak

just replaced transmission gasket and filter, but it leaks. I can't stop that leak. Replaced gasket once again, but it still leaks. I hate this .....
Maybe somebody can tell me what can be the problem?
thanks

Did you try gasket sealer on the gasket?

I find out that leak is coming from some where else. I think i leaks from that pipe there transmission measurer is placed. But I still don't know how to fix it

If the leak is coming from around the dipstick tube at the tranny, there should be a rubber o-ring around the bottom of the dipstick tube. Check with a repair manual, but I'll bet you have to remove the tube from the tranny to replace the o-ring. Good luck.

where can I buy this rubber o-ring?

You can buy the o-ring from an auto parts store or the dealer.

Maybe somebody knows how to remove dipstick tube from transmission?

Maybe somebody knows how to remove dipstick tube from transmission?