Best way to clean radiator

[gold69charger]

What is the best way to clean out the radiator? I was doing my Spring Cleanig and found alot of buildup in the radiator....looks like the previous owner never did a flush and fill! I have the car all back together and would like to some how clean it out before filling it back up with clean fluid. Any chemical out there that will break the crud up?

 

[mark b]

My suggestion...

After just a general drain and flush, get some RMI-25 and run though a few cycles of run/flush/ad new. RMI is great at cleaning up cooling systems.

Depending on how bad the system is, you may need to
power-flush it anyway.