radiator flush and refill

[Ryan Clark]

I have a question regarding the draining and refilling of the radiator fluid. The service manuals say to drain the fluid from both the radiator and engine water jacket. Where on the engine is the bolt to be removed to drain the rad. fluid.? It is a '65 327/300.

I know there have been several discussions regarding the ideal water/antifreeze mix. I seem to remember most people go with a 50/50 mix distilled water/antifreeze. What brand of Antifreeze is most often used? I plan to check the archives on this subject.

Finally, do most auto parts stores take antifreeze? Or is there a preferred method of disposal?

Thanks
Ryan

[John H.]

Re: radiator flush and refill

Ryan -

The only drains for the water jackets around the cylinders are hex-head pipe plugs just above the pan rail on each side of the block, one per side. An incredible amount of rust and crud accumulates at the bottom of these cavities, as hardly anyone ever pulls the plugs and drains the block properly. When you remove them, don't be surprised if nothing comes out - you'll probably need to jam a piece of coathanger wire or a scratch awl up into the hole to break the accumulated crud loose, then watch out! Coolant will POUR out - have your drain pan handy. When you replace the plugs, put some anti-seize on the threads so they'll be easy to remove the next time (the first time can be an adventure). You need to drain both sides - they're independent and not cross-connnected.

Some auto parts stores will take used coolant for disposal, some won't; check with your local city hall for the nearest toxic waste disposal facility or their schedule for the annual "we take anything" day at the community waste disposal location. Once a year, ours will take anything except latex paint (?).

Most folks prefer the standard 50-50 mix of anti-freeze and distilled water; change it out every two years and its corrosion-preventive additive package will do its job. Don't use the "environmentally friendly" propylene glycol-based anti-freeze (like "Sierra", etc.); its heat-transfer effectiveness is about 10% less than conventional ethylene glycol-based anti-freeze; if your cooling system is marginal, the propylene glycol-based coolants will just make it worse.

[John H.]

Re: radiator flush and refill

Ryan -

The only drains for the water jackets around the cylinders are hex-head pipe plugs just above the pan rail on each side of the block, one per side. An incredible amount of rust and crud accumulates at the bottom of these cavities, as hardly anyone ever pulls the plugs and drains the block properly. When you remove them, don't be surprised if nothing comes out - you'll probably need to jam a piece of coathanger wire or a scratch awl up into the hole to break the accumulated crud loose, then watch out! Coolant will POUR out - have your drain pan handy. When you replace the plugs, put some anti-seize on the threads so they'll be easy to remove the next time (the first time can be an adventure). You need to drain both sides - they're independent and not cross-connnected.

Some auto parts stores will take used coolant for disposal, some won't; check with your local city hall for the nearest toxic waste disposal facility or their schedule for the annual "we take anything" day at the community waste disposal location. Once a year, ours will take anything except latex paint (?).

Most folks prefer the standard 50-50 mix of anti-freeze and distilled water; change it out every two years and its corrosion-preventive additive package will do its job. Don't use the "environmentally friendly" propylene glycol-based anti-freeze (like "Sierra", etc.); its heat-transfer effectiveness is about 10% less than conventional ethylene glycol-based anti-freeze; if your cooling system is marginal, the propylene glycol-based coolants will just make it worse.

[Jack layton #896]

Re: radiator flush and refill

When you take out the hex head bolts use a hex head socket. NOT a 12 point. These things will require a LARGE force to rotate due to rust. A 12 point will "round" the head off before you get enough torque to move it. Replace with brand new hex head bolts. The old bolts will be corroded on the ends , not to mention the threads and the head by the time you get it out. Plan on using a 1/2" breaker bar with the 6 sided socket . These things can be like "Jack the Bear " to get out. Don't even bother starting with a 3/8" ratchet and a smile on your face!
You might try rust penetrating fluid and tapping with a hammer if the going gets rough. Good luck!
P.S. I did my 1965 327/300 AFTER I took the motor out for a rebuild. Easier to gain access but I still needed the 1/2" breaker bar

[Jack layton #896]

Re: radiator flush and refill

When you take out the hex head bolts use a hex head socket. NOT a 12 point. These things will require a LARGE force to rotate due to rust. A 12 point will "round" the head off before you get enough torque to move it. Replace with brand new hex head bolts. The old bolts will be corroded on the ends , not to mention the threads and the head by the time you get it out. Plan on using a 1/2" breaker bar with the 6 sided socket . These things can be like "Jack the Bear " to get out. Don't even bother starting with a 3/8" ratchet and a smile on your face!
You might try rust penetrating fluid and tapping with a hammer if the going gets rough. Good luck!
P.S. I did my 1965 327/300 AFTER I took the motor out for a rebuild. Easier to gain access but I still needed the 1/2" breaker bar

[Duke W.]

Re: radiator flush and refill

Sage advice from Jack. If you don't have a 12 pt. (I think it's 9/16") socket go out and buy one. Many have rounded off the hex with 12 pt sockets.

I now use Havoline Extended Life anti-freeze (GM Dexcool). Its organic corrosion inhibitor package will provide better protection for aluminum and there are no inorganic salts to clog up the radiator and heater core tubes, but the extended life attributes are lost if conventional inorganic inhibitor anti-freeze has ever been in the system, so the two year life remains.

If you swtich to Dexcool, be sure to thoroughly flush your system until it is purged of all the old coolant. Backflushing cold through the heater hoses will flush most of it, but do one or two hot flushes by filling the system with water, run it until it reaches operating temp for five minutes, then drain and refill after allowing about two hours for the engine to cool.

For the final fill your need two gallons of Dexcool and two gallons of distilled water.

Duke

[Duke W.]

Re: radiator flush and refill

Sage advice from Jack. If you don't have a 12 pt. (I think it's 9/16") socket go out and buy one. Many have rounded off the hex with 12 pt sockets.

I now use Havoline Extended Life anti-freeze (GM Dexcool). Its organic corrosion inhibitor package will provide better protection for aluminum and there are no inorganic salts to clog up the radiator and heater core tubes, but the extended life attributes are lost if conventional inorganic inhibitor anti-freeze has ever been in the system, so the two year life remains.

If you swtich to Dexcool, be sure to thoroughly flush your system until it is purged of all the old coolant. Backflushing cold through the heater hoses will flush most of it, but do one or two hot flushes by filling the system with water, run it until it reaches operating temp for five minutes, then drain and refill after allowing about two hours for the engine to cool.

For the final fill your need two gallons of Dexcool and two gallons of distilled water.

Duke

[Art B.]

Re: radiator flush and refill

Jack:
The previous owner of my '61 managed to round off the hex plug on one side of the block. Any suggestions on how to get it loose? It does not want to move.
To make it harder, there is not much room to really get a grip on it.

[Art B.]

Re: radiator flush and refill

Jack:
The previous owner of my '61 managed to round off the hex plug on one side of the block. Any suggestions on how to get it loose? It does not want to move.
To make it harder, there is not much room to really get a grip on it.

[Jack layton #896]

Re: radiator flush and refill

You might have to learn to live with that one. Things could be worse. I think I would leave it until I pulled the motor for other work then make a significant effort with the improved access. Working in the limited space available under the car may cause you to worsen your situation. Out of the car one could try penetrating fluids. physical shock, heat from a torch and/or chemical bath when you "boil" the block(which is what I did to mine using a lock wrench).

[Jack layton #896]

Re: radiator flush and refill

You might have to learn to live with that one. Things could be worse. I think I would leave it until I pulled the motor for other work then make a significant effort with the improved access. Working in the limited space available under the car may cause you to worsen your situation. Out of the car one could try penetrating fluids. physical shock, heat from a torch and/or chemical bath when you "boil" the block(which is what I did to mine using a lock wrench).

[Jeff A.]

Re: radiator flush and refill

On my 70, taking off the goose neck and screwing out the temperature sensor seemed to drain the block real well.

[Jeff A.]

Re: radiator flush and refill

On my 70, taking off the goose neck and screwing out the temperature sensor seemed to drain the block real well.

[Larry B. Seaney]

Re: radiator flush and refill- try this

A trick I read in a car mag. said to heat the plug with a hand held propane tourch and then put some parafin wax on the plug and let it cool down. Repeat the process several times. Supposedly the heat/cool cycle draws the wax into the threads and aids the process of removel. Don't get the area so hot that the wax burns off.
I havn't tried this yet so can't promise anything.
Good Luck!
Larry

[Larry B. Seaney]

Re: radiator flush and refill- try this

A trick I read in a car mag. said to heat the plug with a hand held propane tourch and then put some parafin wax on the plug and let it cool down. Repeat the process several times. Supposedly the heat/cool cycle draws the wax into the threads and aids the process of removel. Don't get the area so hot that the wax burns off.
I havn't tried this yet so can't promise anything.
Good Luck!
Larry