What is the best material to use to bypass the heater core? Any advice would be greatly appreciated. Has anyone ever done this before?

 

just buy two brass fittings that will fit tightly inside the water hose and a length of hose to make the bridge and four hose clamps to secure it all, if you have enough extra hose already under the hood then just one fitting and couple of hose clamps will do it, all you're doing is shortcutting running the hot water from the engine into the interior of the car ... I just had mine replaced, $860, so if you live somewhere you can do without a heater and you're wearing the car out or just need a break until you can afford the repair that will do it ... dunno what model you have, on mine there are two hoses running into the firewall about right in front of the steering wheel so I would just have to take those loose and splice them together, the water will leak out or evaporate out of the heater core fairly shortly, depending on how hot it is where you live ... considering when you posted this you've probably already dealt with yours, but maybe the shortcut will help someone else out with a temporary "get by"