4.8is N62 coolant leak back of engine questions

[nextelbuddy]

so 2 years ago i did a cooling system refresh. i did everything BUT the coolant transfer pipe under the manifold. radiator, water pump, all hoses, expansion tank, thermostat with temp sensor and housing

everything has been fine but now i'm noticing small coolant leak on the ground since i'm parked on a slight hill.

last month i got the low coolant message and topped off. i haven't got it again but i know its coming.

i plan on doing the transfer pipe just been putting it off, price of the AGA pipe has me sweating a little

the question i have is for the Y pipe i keep seeing people talk about at the rear, is it also UNDER the manifold with the transfer pipe? or is it accessible/replaceable with out having to remove the intake manifold?

i'm assuming that it is not a good thing to put off the transfer pipe if the valley pan area is filling up with coolant? doesnt it run the risk of seeping into the intake manifold eventually causing other issues like knock and eventually engine failure like hydrolock etc.



****edit never mind the Y pipe i see is just the expansion tank pipe 17127509967 which i replaced during my cooling system refresh already.

so looking at other pictures it looks like there are no coolant hoses in the back and the only place that would be leaking is the transfer pipe in the rear?

so the pictures i always see with valley pan filled up with coolant.. is that people that have not replaced anything including the Y pipe and it leaks into it? but if you did everything BUT the transfer pipe then it would only be leaking in the rear of the engine and my valley pan shouldn't be filled up with coolant?