How do you completely flush engine, radiator, heater coolant on a Slant 6?

[Prints Valiant]

The procedure I have is:

1. Opening the radiator drain, removing the block coolant plug, and removing the thermostat.
2. After draining, close the radiator tap and, using a garden hose, fill with tap water.
3. Start the cold engine.
4. Continue running tap water into the radiator until it's coming out clean from the block coolant drain.
5. Shut off tap water.
6. Shut off engine when water from the engine block is down to drips.
7. Open radiator tap to empty its water.
8. Reinstall thermostat and block drain plug. Tighten radiator tap.
9. Refill radiator with water/antifreeze mix.
10. Start engine. Turn heater setting all the way up. Keep topping off.
11. Cap radiator and run until hot.
12. Check for leaks and accurate thermostat function.

Thanks for comments and suggestions!

 

[Oldmanmopar]

Pick it up by the tailshaft with the wrecker and let it drain out the front.

 

[Prints Valiant]

Not enough room in the carport. My other option was the shop vac.

 

[413]

Modified idea from 40 years of this.

1 Drain radiator
2 remove block plugs & drain
3 disconnect both heater hoses and flush core with water.
4 connect water hose to a heater hose pipe and rinse block
5 Close radiator drain, remove lower rad hose and block lower hose connection. I use a gloved hand. Fill radiator, remove hand and drain radiator.
6 close all drains, install hoses and block plugs. Fill with water and drive. Drain again and surprise it will not be clear water.

 

[slantsixdan]

"Turn the heater all the way up" is needless and pointless. On '65-'70 cars with factory A/C, the heat or defog should be switched on, but the temp slider and fan switch settings don't matter. On '71-up cars with factory A/C, just make sure MAX A/C mode isn't on; here again, the temp slider and fan speed don't matter.

Beyond that, the procedure you describe is fine for a system that was all new and perfectly clean (including the engine) within the last five years or so. Most Slant-6 engines and vehicles do not fit that category. Over the decades, the engine will accumulate mud in the cooling jackets. A water flush won't remove it. Neither will a chemical flush; you need to go in there and physically dig at it. See here.

 

[pa340dart]

If you search Clean radiator, cool
By Rice Nuker Feb 5 2012
First post has a good procedure for flushing the coolant system
Just found it earlier going to give it a shot
Tried flushing it water but I don’t seem to get any flow from the block drain plug - lots of rust though
Used 1-1/4 rubber Fernco with 1-1/4 pvc to hook up hose barb and drain. The radiator is out out and also heater delete car
Going to try his procedure this week