Restricted fitting to replace heater QD. Udated Delco fitting 15-33220

[Stringer]

Penetrating oil is useless on pipe thread. Pipe thread seals by deforming the threads, making an air-tight seal. The penetrating oil can't get in to do any good. If it could, coolant would be leaking out.

ok ill skip it then. did not realize what it is until i have it out, and did not know about pipe thread either. Any removal tips for something like this?

there is a small amount of coolant crust around it so i assume it is leaking a small amount tho.

 

[Schurkey]

Could be "coolant crust" from leaking out the seal/hose on top rather than threads from the bottom. You'll know as you try to unscrew it. Either it comes out nicely and you have a big smile; or it crumbles and things get "interesting".

Even if it crumbles, it may be that you can unscrew the remnant with an appropriate Easy-Out; or hack-saw blade down the middle until you remove a lengthwise piece, and then the rest pulls out. Sort of like those building demolitions where they set off charges, and the thing collapses straight down. Or a couple airplanes into the WTC. If it crumbles, you're gonna be doing "controlled demolition" of the remaining piece.

My '88 OEM quick-connect rotted out so long ago that I don't really remember whether it was in one piece or thirteen when I got it all out. I know that the Dorman quick-coupler I replaced it with went ~20 years in that engine, threaded out nicely, and got re-used on the next engine because it still looked perfect.