Hotend leaking/extruder issues  

Hotend leaking/extruder issues

So the Mk3 is my second printer, I assembled an MK2S a year ago and it works great.

Assembled the Mk3, got one print out of it, then the filament broke off just above the PETG tube with a blob so I can't push it through, can't move it with heat. Couldn't clear the jam so I had to take apart the extruder and pull out the hot end, heat it with a heat gun and clear the PETG tube. I reassemble it (without heat) thinking I'm good to go, tightening it in such a way that the connector between the heat sink and the heater block allows for the nozzle to be flush.

Start printing again and half way through the print I notice large blobs all over the place. I stop it and take a look and notice the hotend is just leaking everywhere. Look through the forums, and there are suggestions that the hotend needs to be assembled while hot. Disassemble the whole hotend again, heat the whole thing up with a heat gun, reassemble the whole thing, still having the same issues. Hotend is leaking at the block.

Any advice on what to try next?

I am so frustrated. The Mk2 was build and done, but the Mk3 seems like this has just been an ongoing disaster because of this jam.