Coolant system flush

[chilwil86]

I have a sbc gm 350 crate engine blew a head gasket had black milkshake in radiator. Replaced the head gaskets and I'm now trying to flush out the black brown water. the block sat all winter with no heads on it so it's a little rusty too. Runs great just can't get rid of tea water, any ideas tried dawn dish washing liquid and greased lightning , I've heard white vinegar any opinions. Thanx

 

[choppedtop]

Not tried vinegar, but I hear it works better than any on the market flushes. My block was rusty and after a few (5) thermostat changes with new af each time, it cleared up.
Lee

 

[Screaming Metal]

I have a sbc gm 350 crate engine blew a head gasket had black milkshake in radiator. Replaced the head gaskets and I'm now trying to flush out the black brown water. the block sat all winter with no heads on it so it's a little rusty too. Runs great just can't get rid of tea water, any ideas tried dawn dish washing liquid and greased lightning , I've heard white vinegar any opinions. Thanx

Take off your top radiator hose, point it off to the side (might have to loosen the radiator clamp on the housing to rotate that top hose where you want it to point), take out the thermo out of the housing, get a garden hose, put it in the filler neck on the radiator so it won't fall out, turn on your water and then start the motor, its gonna make a mess so back up and give it some room, but it'll get flushed out good. Stop after it runs clear for about 10 minutes....

be sure take precautions to keep the garden hose outta the fan....

 

[Screaming Metal]

After you've done that, radiator hoses connected back up, Flush it once with a liquid flush (Prestone) running straight water, drain it, you'll be good to go. Add your water/antifreeze/coolant and be sure to replace your cap also....

 

[ellis8500]

I made a pipe that plugs into the fan switch location on the intake manifold. Other end has garden hose fitting. Hooked it up an let it run until all water coming out clear.