My van's heater-core began leaking coolant on the passenger-side floor. Not Good, when you've a cat in there!

Couldn't afford a replacement, and needed to prevent that leak ASAP... I asked-around and someone suggested to just bypass the darn thing. Duh.

I bought some hose, and some hose-couplings, the kind with barbs on both sides... and some hose-clamps. My favorite hardware-store came through with all the goods. found a place to do the job... and...

The friggin' hoses going to the heater-core have a special connector that happens to be attached to the hose via a crimped metal ring. My hose-couples wouldn't work because the metal crimp prevents the hose from stretching *at all*, even the tiny amount needed by the hose-barbs.

So I'm sitting there trying to figure out the solution... 

I have my dremmel, maybe I could lathe off the barbs... 

I could cut off the connectors, just use regular ol' hose-clamps on the new core, when I get one... but, no, the hose's inner-diameter is the same as that of the pipes on the core, they're meant to butt-up to each other, not overlap. AND the hose-walls are extraordinarily thick, stretching would be difficult, to say the least... and stretching *that much*? 

so, more pondering, back to dremmel-lathing... not mobile till the solution is implemented, far-ish away from parts stores... tapping my sharpie on my hand, I realize the darn sharpie is darn-near exactly the right size to be used as a hose coupling. And, it's slightly tapered. And, I just happened to have two.

Cut off end of sharpies, remove tip and innards, insert tapered end into crimped hoses until it stops, insert bypass hose on remaining inch of sharpie. BAM.

I drove hundreds of miles like that.

...until... stupid me, thank god the cat wasn't around at the time...

the bypass hose must've expanded with the heat and eventually slid off the sharpie. I hadn't bothered closing up the heater-box... so instantaneously the cabin was filled with coolant-vapor. (thankfully, mostly water, at this point, but still, quite hot and terrifying). Somehow managed to not swerve into a telephone pole or another car at 50MPH, did some cleanup, cut off the widened ends of the bypass hose, refilled the coolant tank with water, and this time used duct-tape to pull the two hoses tight up to each other.

Drove well over 1000mi like that; minor leaks from time to time, readjusting the duct tape, cutting off the widened hose ends, but nothing particularly traumatic, just minor leaks now contained in the engine compartment... 

...before finally investing in a piece of copper pipe to replace the sharpies, and proper hose clamps on that pipe... still couldn't clamp to the original hoses, because of the crimp, so sat in a Lowes parking-lot past closing-time tapering the pipe with a hammer, and eventually pounding it into the hose so tight I was certain it wouldn't pop out.

Countless miles like that, but it was starting to get cold, so finally managed to buy the heater-core replacement and installation went without a hitch. Oh, and much thanks to a generous and thoughtful person, 'round here, for helping make that possible, as well as the refilling with proper coolant before the freezing weather set in!