Flush engine block coolant?

[crutch]

My coolant system was completely restricted with lots of rust and gunk. I'm replacing the radiator, water pump, thermostat and hoses but wanted to make sure the engine block was relatively clean before I start pumping new coolant back through the system and potentially gunk up the new radiator. Any recommendations on best way to do this? I have the new water pump and thermostat installed but haven't hooked up radiator yet.

Can I just spray a garden hose in the lower radiator hose and then drop the upper radiator hose into a bucket?

I have a 302. Thanks for the help!

 

[blubuckaroo]

When they're gunked up like that, I like to remove the thermostat, dump a bunch of trisodium phosphate powder(the same stuff you wash walls with before painting) into the thermostat opening, fill the cooling system with water, and let it sit for a few hours before flushing it out. You'd be surprised how much more crap comes out.
Don't forget to flush the heater core too!

 

[904Bronco]

You might also want to remove the 1/4 drain plugs on the block, one on each side of the block, and flush out the lower end... Drivers side is to the rear, Pass side is forward. If you remove them and nothing comes out, them some "mud" might have built up there behind them, use a small screw driver to open them up...

 

[phldwsnoc1]

All good advice. Flush with a garden hose through the heater connections until the discharge is clear.

 

[Pa PITT]

I did a chevy truck many years ago... & It was summer time.. But I put in one of those ''T'' into the heater line. Then I could attach a garden hose to it.. I added the Rad Flush .. Soldier Seal brand I think.. I'd open the pit cock & leave the rad cap off .. I'd let it run for 30 minutes & every time I Rack off the motor ... About 2 minutes a lot more crap boiled out of the radiator.. I'd button it up & drive it hard & flush it again & more crap came out . I did this for over 2 weeks & finally it was clean.

 

[genteca]

Flush

I flushed my 1989 5.0 before I started running it. I also had a new radiator,so I wanted to screen the top hose just before radiator to make sure no rust got in. I would drive mine 5 to 10 miles and check after it cooled. Every time I would find about a water bottle cap of rusty scale. Finally cleared up after all summer. I would recommend doing this.