I am curious to get everyones thoughts on cooling system flush and additives.
I have a 71 442 (orig) and want to flush the cooling system and prep for storage. I have a flush Tee plumbed in at the heater core line going into the firewall that was installed before I got the car. I am not quite sure if it is the inlet or return (I'm not looking at car) What is the best method to flush the cooling system and radiator? are there any products that help to flush out sludge and debris if any? How do I make sure all water from flushing is out?
I plan on adding a 50/50 mix of anti freeze and distilled H20 after flushing.

 

I always liked those flush tees. I haven't looked to see if they still sell the kits. You also need an adapter to hook a garden hose to the tee and there was a diverter spout that went in the top of the radiator to direct the water away. Just turn on the garden hose and let it blow out over the grill with the engine running and the heater on. I normally left the radiator drain open while flushing too. let it run until the water turns clear. Check the auto parts stores to see if you can still get the kits for the rest of the parts.


Edit: I almost forgot, there are plugs at the bottom of the block on both side to drain the block. But you never get all of it so plan a stronger mix than 50/50 to compensate for what you can't get drained out.

 

The best way is to remove each of the hoses and do each section separately. Using a water flow reverse from the normal does even better.
Here is how I did mine, mentioned in these two threads...

https://classicoldsmobile.com/forums...tml#post276477

https://classicoldsmobile.com/forums...html#post40787

Of course this does not need to be done with each coolant replacement. Every 10 years maybe, depending how long the car sits.

 

As already noted, reverse/back flush is the way to do it.

 

Paul,

Here is what I do:

1. Add 2 bottles of Prestone Flush to the radiator, and get the car up to operating tempreture...have the heater on hot. Let it run for 10 minutes. Turn off.
(be careful when removing the radiator cap)

2. Using HOT tap water, connect a hose to the tee. Do you have the adapter? The Prestone kit comes with a plastic pipe that goes into the radiator opening. I add a 4 foot piece of heater hose so the coolant does not go all over the core support. With the car running and the HOT water hooked up to the tee, let it run until the water comes out clear...about 5 minutes. Heater is on.

3. Open the radiator petcock, and let all the water drain out.

4. I add 2 gallons of 100% green antifreeze to the radiator.

5. Start the car, and wait until the thermostat opens (the top hose will be hot). This "burps" the air out of the system.

6. Add 50/50 mix up to about 1.5" from the top of the radiator.

The other Paul

 

Thanks for the advice everyone. Paul I pm'd ya, I've been out of the car scene for a while.