Weird Leak
 

Attachment 208213
http://www.ziptied.com/Coppermine/al...ines-miata.gif

Leaking at the 90* @ #2. Hose goes from #2 into #1.

I replaced the hose and water is still leaking. Appears that the metal tubing sprung a leak. I'm assuming this whole unit needs to be taken off and welded. Are there any other alternatives you guys can think of? Or should I just cut the 90* bend part where it's leaking?

Looks like a pain to remove.

Edit: this is coming from the heater and runs from under the exhaust manifold towards the front to the thermostat.

Thanks.

I'm trying to recall where this is in relation to the other coolant lines up front. My memory is shit.

2 things:

If that coolant line is coming from where I think it is (near the t-stat if memory serves) you should check for clogs upstream from that point. I know there is a point around there that is notorious for clogging and causing issues (happened on my old motor).

If it isn't a clog, you can repair a leak with black RTV. I did it on my miata at the heater core lines and patched a huge crack in my integra's old radiator. This is if you're absolutely sure you are leaking from that point and not somewhere else dripping down.

There is an oring on the solid line where it connects to the metal pipe your onsite pics i suspect water pup failure. Some RTV or JB weld will help u for alil while if u have hairline cracks however i would not trust that as a permanent solution.

That metal 90* fitting is pressed into the water pump inlet neck that bolts to the water pump. Just get a new (used) water pump inlet. Fixed.

You might be able to braze that, welding isn't an option for steel tubing to aluminum. Like pat said that fitting is pressed into the housing, there is no other sealing element there besides a press fit piece of tubing into a soft cast aluminum housing.
If it's super loose you might be able to get a "hardening" thread sealant, pull the tubing out and then re-seat it with the sealant.

Can the water pump inlet be separated from the metal tube that runs under the exhaust manifold? Or is it all 1 piece?

The metal tube that goes under the manifold is sealed into the water pump inlet with a fat o-ring. Nothing else, it pulls right out.