OK, new to this. have a '99 4.0. The heater core hoses. One on top and one below. Which is the outlet hose? Top or bottom.

 

The inlet hose is the one that comes from the head

 

OK, I am newer than even that. Looking for top or bottom because I don't know what a "head" is.

And why isn't there a physical manual out there that says "this is the lower radiator hose" and "this is the starter". I have the Haynes original Jeep shop manual and it is near useless. Or is there such a book, short of the $300 garage MOPAR set.

 

Your hoses could have been switched if replaced. So look for the one that comes off that thing on top of the engine. The other, the outlet comes off that thing on the front that has a belt pulley on it

 

OK. They look set up the same as all of the stock photos of 4.0's in 99 Cherokee's and neither goes to the top of the engine. Both seem to go to the water pump (?). One clamped directly to it and one is clamped onto a (very rusty) metal "L" tube that goes to it.

I am having fun with working on my XJ but MAN it is difficult to get info. I am good on the 'Net and it is still a struggle to find info. I have seen 100's of YouTube videos specifically on XJ mods and maintenance but wow. Certainly no instruction manuals on these babies. Both simple and complicated. Like my wife!

 

Good news. I pulled both pipes and flushed the core with hot water (fail, still no heat), then radiator flush followed up with compressed air (that did it). Now, I have happy heat! Next is new diff cover and fluid change, oil pressure switch, tie rod ends, exhaust and muffler, floor pans, oil pan, and rocker/sliders.

Good times!