I installed a HeaterCraft heater, basically a car heater that makes use of heat from the engine. 5/8" hoses tie in to engine's coolant system and run under the floorboards, then back up a foot or so to the heater. It's going to be a bit of a trick to fill the hoses and the heater with anti freeze without leaving any air pockets which would significantly affect efficiency. The heater is a high point in the system (though it is lower than the engine itself).

I may use a nylon elbow on each hose after it comes up thru the floorboard, then run a short section of hose to the heater. This would save from too much bending of the hose. I was thinking of drilling and tapping the upper side of the upper elbow at its thick part and screwing in a SS bolt. This would give me a way to bleed off any air that might accumulate at the high point of this side of the system.

Any reason not to do this? The only one I can think of is adding a potential leak point but using a sealant should make it pretty leak proof.

Thanks,
Max