Here's how I did it.


1. I drained the lower radiator hose and the drain cock (with the heater valve all the way hot)
2. Removed thermostat housing and pulled the t'stat (reattached housing)
3. Blasted water from hose in-through the lower radiator hose to back flush it.
4. When the only thing coming out of the radiator was water, I stopped
5. I reattached the lower hose and poured in exactly half of the coolant system volume.
6. Started filling in water, and when it got to the max, I started the motor and squeezed the radiator hoses. (Keep in mind the heater is still at HOT, and thermostat is not in place, but housing is attached)
7. Continued stopping engine, puttin water in, and re-circulating.
8. Eventually it was finished, so I put a new thermostat back in with the bleeder valve thing at the top).
9. Ran the engine again, and topped it off with water again.

It worked perfectly and the heater hasn't been better.

Hope this helps.

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-BoominVolvo