What leaks coolant on the bulkhead under the AC lines?
 

As per the title. I am back to finding a coolant leak. The leak appears under the AC lines where they cross the bulkhead just to the left of the engine when looking into the engine bay.


Is it the heater coil in the passenger compartment? Is this the bit where I get to disassemble the entire dashboard to get to it? Is there a DIY?

The heater core is sealed in the heater box and the box has drains (which typically drain AC evaporator condensation, on to the transfer case/forward output flange, conveniently), a leaking heater core is usually evidenced by the smell of evaporated coolant in the cabin/foggy residue on the glass and visible evidence of coolant at the drains. Sure it's not a valley pan/rear coolant pipe leak on the engine?

Nope, valley pan shows up at the bottom of the bellhousing. I did my v-pan a few months ago and she is bone dry up there. There is clear evidence it leaked under the AC pipes. I'll take picture next time I get in there.