Heater core backflush w/ pics - AudiWorld Forums

So my heat doesn't work, and I was thinking I should try flushing my heater core, but I don't fully understand this DIY and I don't want to mess anything up...

I just had a full coolant flush done so I'd rather not have to do a full coolant flush again, and that's where I'm confused, does flushing the heater core through those inlet/outlet lines affect the coolant at all?

Or can I flush it this way and just connect the hoses back and everything's just dandy again? I guess my question is "do I lose coolant or put water in the cooling system through flushing the heater core this way,"

because I read somewhere the heater core holds 24+ OZ of coolant, IDK, just a confused noob.

And to review this process, all he does is connect a piece of tubing to the INLET, runs tubing to that 5 gallon jug, then connects a garden hose to more tubing, that connects to the OUTLET, and runs water through it -- and runs the water until stuff coming from INLET-to-JUG is clear?

I am going to shoot myself in the face if I have to replace my heater core.

 

You loose coolant. The heater core is full of the same coolant as the rest of the engine. If it were me, after the flush I'd blow the clean water out of the core, then replace with 50/50 water/G12. You'll still have some bubbles there, but they should work out in a few miles.

 

Blow it out with an air compressor? Then add coolant through the inlet hose to the heater core or where? Sorry for the stupid questions!

 

Well me, I'd just put my mouth on it. Doesn't make any difference which tube you fill. It's just a hoseshoe-shaped tube with fins around it.