1967 radiator refill

[Mark Jekot]

Now that I have my original, aluminum, 327/300 radiator pulled, repaired, and re-installed, I need to fill it back up. I do not know what the process is to refill the system. I did not open the block drain plugs when I drained it. So, my questions are as follows:

1. What is the best antifreeze to use here in Denver, CO ?
2. What is the process to refill the system ?
3. Will the fact that I did not open the block drain plugs present a problem ?

Sorry for the naive'te but I'm learning here.

Mark #33661
Denver, CO

[Wayne K.]

Re: 1967 radiator refill

If the coolant you took out came out clean you probably will not have to flush the system. Otherwise purchase some engine cooling system flush and follow the directions. Make sure you have the temp control pulled all the way open when flushing and/or filling. Any name brand coolant mixed 50% with water should work fine. I like to mix with distilled water. As the fill tube is small going from the tank to the radiator take your time in pouring in the mixture to avoid trapping a lot of air in the system. As the tank empties add some more. I like to stop after every few quarts and wiggle the car sideways to help let the air escape. After no more goes down with the tank about half full or less I start the car and let it warm up at an idle. As any trapped air escapes it will push the mixture back up so be prepared for some overflow. Once the thermostat is opened the level will go down so slowly add some more until the tank is about half full and then put the cap on so the system builds up pressure so you can check for leaks. After it is completely cooled check the tank and fill to half. After a few drives it should stabilize so check again when cold and make sure that there is at least some mixture in the tank. Higher altitudes may require a different mix ratio which should be listed on the product. Take your time and good luck.

[John H.]

Re: 1967 radiator refill

Use conventional ethylene glycol-based anti-freeze, not the much-hyped these days "Environmentally Safe" propylene glycol-based anti-freeze like "Sierra" brand; the "Sierra"-type coolants are about 10% less effective in transferring heat and can cause cooling problems in cars whose cooling systems are already marginal.

[Dennis F. King]

Re: 1967 radiator refill

Mark
Your getting good information. Here is something to consider and since I don't know anything else about your car it may or may not be appropriate. Are all the hoses fresh with in the last 5 years? If not replace all of them. What do you know of the thermostat, new or old? If you can get to the block plugs it gives you the opportunity to get some crud out of the bottom of the block. As a matter of fact you may have to poke a sharpe object into each after the plug is removed to open it up. On filling the block, no air will get trapped if you fill it by removing the thermostat housing. Also, you can back flush the heater core as you remove the hoses. Hope this helps. Dennis

[Duke W.]

Re: 1967 radiator refill

Remove the plugs and drain the block. The anti-freeze should be changed every two years regardless of mileage. I recommend GM Dexcool (Havoline Extended Life - widely available.)

Your system capacity is about 16 quarts, so install two gallons of anti-freeze and two gallons of distilled water.

Duke

[Mark Jekot]

Re: 1967 radiator refill

Thanks to all for your input. As always, it is very helpful.

THANK YOU

Mark #33661
Denver