How do I flush out my heating core? My car is cold and I thought I needed to bleed the system but there is no antifreeze coming out so now I wana know how to reverse flush it?

Any help would be helpful thanks

 

I'm planning/needing to do the same thing, but waiting for spring here to do it. I went on you tube and watched a few really good videos (think if you search audi heater core you'll find them). The two that I thought were best were a bit different:

- one guy just used bursts of compressed air through the core, seemed simple, quick and based on his results and others comments, appears effective. I plan to start with this method

- another guy rigged up a small pump and ran a cleaning/descaling solution through cooling system (used bucket/solution/temp hoses and a pump). He also seemed to get good results, but more time/effort/equip needed.