I have a couple interesting bleeding situations I'll need to confront shortly. I am installing an air heater using engine heat. The heater coolant lines run from the engine, down under the floorboards, then up about 6" to the heater. There is no air bleeding valve on the heat exchanger, so it will be a bit of a challenge to make sure there is no air lock at the heater. I am considering putting in a "T" where the outlet coolant line exits the heater, with a 1 ft vertical hose with a cap on the end where I could bleed off any air. It would be nice if I didn't have to add the extra complication of this, am I over thinking it and is there a simpler way to make sure the lines are full and without air trapped ?

I also installed a diesel heater where the fuel line runs under the floor, up a foot to a Racor filter, then down 6" to the heater. The Racor has a bleed port so I think I will be OK with that one.

I'd be interested in any comments from folks who have dealt with these situations.

Thanks,
Max