[Kurt in NJ]

this is a "zoo" flush gun, there is a water valve, and the little lever is the air,put in lower hose, turn on the water, when full of water hit the air, a block can take more pressure,and full pressure, but with radiator it is best to not "hit" it too hard, the air forces the water to nove fast and carry out debris

I know the tool is not common now, but easy to make something like it, just some adapters to adapt hose to the garden hose nozzel, and a fitting---drilled hole for blowgun ---first start with reverse flow, after debris stop reverse direction----then reverse direction again till nothing comes out anymore