I drained, filled, drained my radiator today on my '53 Chrysler. The water in the rad seemed clean and drained well. I opened the petcock on the left side of the block and no water came out. I removed the petcock, thinking it might be clogged with scale and discovered a lot of mud in the block.
I removed the thermostat, lower rad hose and stuck the garden hose in the upper hose. I expected some water to pour out the open block hole, but there was only a little. Hooked the lower hose back up, and again stuck the garden hose in the upper hose. A little more water out of the block, but not a lot.
Any suggestions? I'd rather not start knocking out freeze plugs if at all possible.