Flushing the Block During a Cooling System Rebuild

[uncledavid]

My new Behr radiator just arrived. I changed the water pump and discovered slug and small pebbles of coolant in the pump and block ? I do not want to plug up my new radiator. All the other components of the coolant system are new. Should I:

a) put on the old radiator and flush the system, then put on new radiator
b) put in the new radiator and flush system without worry
c) flush the block in an alternative method

What would you do ? a, b, c, or d (what I didn't think of)

Recommended brand of engine flush ?

[samdemange]

hi,find u a air compressor and make a big flush in ur coolant circuit
rinse with white vinegar ( it dissolves tartar and the limestone ) wait a hour and reflush with air ( all crap blow off )
after u can put ur new radiator

[uncledavid]

I have heard of white vinegar often in the threads. I have the compressor and the front of the vehicle elevated. I could pull off the new thermostat housing and just fill it up.. cheaper by the gallon and not caustic. Thank you for affirming that treatment again.