It's going to be tough say what is causing the water to be brownish because it's probably a number of things. I don't recall how intense of a baselining you are going for (i.e. budget/time evailable) and that will dictate whether you worry about it.
I had a lot of corrosion just about...
I think that looks right.
Is there another set of hard pipes going through the firewall?
Putting aside the fact my rear heater is deleted, your setup looks different than I what I understand should be stock on the left side of your picture.
I'm attaching drawings I found in other threads...
Yeah I ran with the heat on max. My rear heat is bypassed but I imagine it needs to circulate as well. I think the manufacturer suggested I run it for a week and I drove it every day.
I think Joey gave me non-JIS bits as replacements so the next time it would not need JIS. You just need the removal bit to avoid stripping them on the way out.
I used a 1" breaker bar and it came loose fairly easy with a pipe over it for more leverage. There was probably an expletive or two...
You might be able to get a bit of a break on the labor if you already have the radiator out, fan clutch off, belts off, and everything ready to go to get the flywheel off to change the oil pump filter. They can probably change the water pump and pulleys at the same time.
Doing that oil pump...
I really can't tell from the picture. IIRC, there were not a lot of good choices and that made it easier. It's possible I found a good picture on the forums here. My memory has failed me though.
I did something similar. I bought a fairly inexpensive hose nozzle off Amazon that would jam tight into the spare hose and let me control the pressure. There's lots of good ways to do this.
The directions are a bit fuzzy to me but I think it turns the water black. Darker means more rust. I believe you're supposed to see a temp reduction while running with that stuff in the system but I didn't see a big improvement until after I changed all of the parts. I can't say if getting...
I had to use Thermocure but it finally got the rust of my cooling system. Rust apparently is an insulator so it retains heat in places you'd like to cool. I am seeing temps in the 180s now and it only got to 195F briefly on a 100F day recently in stop-and-go traffic.
Before the Thermocure...