@rocky posted:To really drain it, I think it’s best to disconnect one joint on each side in the plumbing underneath.
That way you get a big rush of fluid, hopefully carrying as much gunk as possible out.
My radiator has a petcock on the lower side of the radiator (driver’s side), but I think you’ll only get a trickle out of something like that.
Can you run “radiator flush” for a week or two before you are ready to do the deed? Let it run and circulate, make sure the thermostat opens, and pump it through the engine & cooling system. That stuff is really just a mild citric acid solution.
If you are bringing the car back to life, you’ll want to change all the hoses and tubing as one of your first projects….
Rocky
Thanks for the info! I plan to replace all of the hoses and tubes, just want to flush the system right now. When you say "disconnect one joint on each side in the plumbing underneath" do I need to cut off the hoses and replace them? And if I do will I be able to "insert" the new short length of hoses without having to move the pipes? Thanks