DSR

Can I flush the cooling system on my '65 327 at home? And if so what's the best way to go about it? Or is thier some sort of machine they use in the shop to do this job correctly? Dave

54greg

It definately can and should be done at home. Flushing your coolant is one of the easiest jobs that you can perform. Follow these simple steps:
1. Open the petcock and drain all the coolant.
2. Close the petcock and refill the overflow/radiator with water.
3. Start the car and bring up to approx 100 degrees.
4. Shut off the car. Open the petcock but leave the hose in the top of radiator running slowly. When clean water is flowing out the bottom at the same rate as its going in the top restart the car.
5. Allow the motor to idle-opening the thermostat and flushing out any remaining coolant from the engine. When the water warms and is running clean out the bottom-shut off the ignition and allow to drain fully.
6. Close the petcock and fill with your fresh coolant mix.
7. Start the car, check for any leaks (from the petcock) allow the motor to warm.
8. Shut off the motor and recheck the fluid level.

bweaver999

So what do you do with the fluid? Dumping it behind the garage is not a good idea.

DSR

I take anti-freeze & used engine oil to the dump. They have a spot for hazardous waste, and they let you dump it free of charge! Dave

JoesC5

Anti freeze can be poured down your sanitary sewer system without a trip to jail. It is illegal to dump it down a storm drain or on the ground. At least in Missouri.

ricks327

One important part on draining is to open the two lower drain plugs on each side of the block. This assures a complete draining of old anti-freeze. Once the plugs are out it may require to poke the gunk with a small screwdriver.

65 vette dude

After I drained the radiator,I flushed it out with a mixture of 50/50 white vinigar and water. I also removed the thermostat and flushed without it in. Let engine idle for about 15 minutes and then drain vinigar and water. Refill rad with water and let it idle for a few minutes then drain. Put new Robert Shaw 180 degree hi-flo themostat (about $15 at Summit) and refill with 50/50 distilled water and anti-freeze. Be sure you flush with heater valves wide open. Don't use the commercial flushes.They can be too caustic for 40 year old parts.

chris ritchie

Yes, you can do this at home. And you can do a better job than a shop because it's likely you'll be more thorough than a shop that has to hurry through the job to make money.

Antifreeze is toxic. Not bad. But it tastes sweet and will poison the animals who drink it. If you're a good guy, you'll collect it out of the radiator and dispose of it properly. Most towns have a toxic waste day where you can bring it to a designated place. Most people let it drain out of the car and into the ground. You'll be doing a lot of flushing, so it gets diluted. It won't kill vegitation. If it collects in puddles, and your dog drinks enough of it, he'll die.

In order to make the doing of the job worthwhile, you must get the 2 block drains off. They can be stubborn. There has to be 1+ gallon of coolant in the lower part of the block. It won't come out, despite flushing, unless you get those 2 block drains out. It's easy to round off the heads of the plugs. Give yourself the best chance of success, and use a 6 point socket to get them. You'll also need a breaker bar. When you put them back, put antiseize on them. Someone will thank you 50 years from now.

Flush the heater core separately. Remove the hoses at the manifold and water pump, and stick a garden hose in 1 and then the other. The heater control valve must be open. The "temp" control inside the car opens it.

It's nice to take the thermostat housing off. Not essential, though. If you take the thermostat out, you can flush the block easier. You can also fill through there, which will help avoid air bubbles/locks.

So with the heater hoses off; the radiator petcock open; the thermostat housing off; and the block drains open, attack the engine with a garden hose. Open and close drains and jam the hose in wherever you think. After a while, you should have diluted any antifreeze that drained on the ground, and all the engine drains should have clear water running out of them. You can't do this too much.

Go to CVS or Walmart and buy 2 jugs of distilled water. Go to your FLAPS and buy 2 gallons of Zerex G-05; a thermostat housing gasket; and, a 180 degree Robert Shaw thermostat. Find out how much your system holds and fill to 50/50. Fill it through the thermostat housing with the thermostat out. Finish filling through the overflow tank. You can do all the filling through the overflow tank. If so, you may need to burp the system. After you run it a few times, you may need to add coolant. No matter where you fill it, overfill it. At worst, your system will puke out the overfill after the first few runs, and the level in the tank will settle at about 3/4 full. If it doesn't puke, it may need burping. Overfill it until it pukes the next time. There's probably a better way to do this, but this way poka-yokes it.

Do this every 2 years.

DSR

Thanks everybody for the help. I've never heard of using distilled water for the rad before, is that normal and what are the pro's & cons of using distilled water in the rad. Dave

chris ritchie

Some people live in areas where the water contains a lot of minerals. I believe that's called "hard" water. Hard water is conducive to electrolysis, which is harmful to metal. Distilled water contains nothing. Nada. Zilch. Maybe I don't need to be too concerned about what's in the water. But with distilled water, I have no concerns. Probably overkill. But it's all of $0.99 a gallon. Cheap insurance. But, yeah, 100s of millions of cars left their factories with tap water. $0.99 a gallon is a bargain to people who spend $100 on wax.

bluestreak63

Cool, I just had to go through this yesterday. Although the block drains were no being cooperative, so I let them be for now. I am perplexed however, that when I filled the system back up with 50/50 mix through the overflow tank, it only took about 10 quarts, when the manual said 16.5. I let it warm up and actually drove it around the block a few times, so I knew it got good and hot. The level in the overflow tank never went down. I know the thermostat works (placed in a pot of boiling water and it opened, then placed back in regular temp water and it closed). There was mention of burping the system? How do you go about doing that? Also, all the heater hoses were hot, so I know coolant was cycling.

I also noticed that the uppper radiator hose could be squeezed quite easily (hot as well). I thought the system was under pressure, so I thought it should have been more firm.

The temp gauge was floating around 180 at idle.

Should I drain again and refill through thermostat housing (as suggested by Chris)? And refill the remaining amount left of the 16.5 quarts in the overflow tank?

Thanks...

JohnZ

That's because there's a little over a gallon of coolant trapped in the bottom of the water jackets around the cylinder walls on each side; it's below the level of the water pump holes, and the only way to drain it out is through the block drain plugs on each side.

blueray

I'm doing this process today. I have a 327 car. I found the block drain on the driver's side but don't see one on the passenger side. Am I overlooking something or is there only one a 327? I got a lot of fluid out.

I'm planning to pull the t-stat and run water through the hole to flush block, is this the best way or is there something better?

Thanks
Bryan

ricks327

There is one on the passenger side and it is close to the boomerang spark plug shield. Not easy to see or to get to though. As John has stated you have to open these two plugs to properly flush your system.

blueray

That's the shield which goes from the front motor mount to behind the starter? I pulled that loose and didn't see it. Guess I'll look again. I really want to make sure I get it all cleaned out.

Anyone have a picture? I could swear I didn't see anything!

Bryan

blueray

GOT IT! Somehow I missed the plug behind the shield. Thanks for the suggesetion. Should be able to get it back together in the near future.

rongold

While you're down there, get yourself 2 radiator drain valves and install them in place of the plugs. This way, all you have to do to totally drain the block is open the 2 valves. You're looking for valves with a 1/4" pipe thread. On a big block, if I remember correctly, 1 motor mount gets in the way, and on a small block, the shielding might also get in the way, but if you can do it, it will make the job much easier the next time.

RON

GaryS

Distilled water with your favorite antifreeze (mine is Zerex G-05) is the recommended method by most manufacturers as I understand it. The good thing about distilled water is that you are not introducing minerals, which will soon be contaminants, into your cooling system. I have always assumed (correct me if I am wrong guys) that the white precipitate that you see on your cooling fins starts out as the minerals as they settle out of solution.

There are not ANY cons to using distilled water, that I know of.

As suggested, if you do everything that others have mentioned, but fail to drain the block at the block drains, you are leaving a significant amount of old water/coolant in your block. I just did this four days ago on my 72 LT-1 and getting the block drains out was a PITA. This is espcecially true if you still have ignition shielding in place. It can be done, but it ain't easy.

Gary

bweaver999

Any tips for getting to the block drain plug on the passenger side? Finally found them, both drain plugs are directly behind the lowest point of the ignition shielding. The drivers side was pretty easy to get to but the passenger side shielding appears to be attached behind the starter. Do I really need to pull the starter?

ghostrider20

If you can see it, just get a series of 3/8" extensions for your ratchet. I think the square plug is 3/8" so a socket extension will plug right in.

Mark