'63 Removing Expansion Tank and Draining at Heater Hoses Before Draining Radiator

[Frederick H.]

Changing out the battery, I completely forgot to drain the radiator prior to removing the expansion tank and draining what would drain at the T connection. I do not have time to do a complete flush - guessing I may get air in the system and will need to let the tank "belch" air until it subsides? On a top-fill radiator, I would raise the front of the car to get the air positioned correctly. Any input on the drain order? I removed the tank as there was a lot of brown sludge when I siphoned the coolant out.

Thanks in Advance,
Fred

[Duke W.]

Re: '63 Removing Expansion Tank and Draining at Heater Hoses Before Draining Radiator

If you have "brown sludge" in the expansion tank your cooling system is likely in bad shape and there's also likely a lot of gunk at the bottom of the block.

You need to do a complete drain and flush, including removing the block drain plugs.

As the saying goes you can pay now or pay more later.

I've never had a problem refilling my SWC's 340 HP engine after a complete drain, including the block. You'll need two gallons of Zerex G-05 and two gallons of distilled water. Add the G-05 slowly until the expansion tank is near full. Then bounce the car up and down. This should allow more to get into the block and drop the level in the tank. Repeat until it will not take anymore.

Then with the cap off start the engine and watch the temp gage. When the thermostat opens the level in the tank should drop. By this time you're probably down to the distilled water. Bounce some more and see if you can get more fluid in. When it won't take anymore, take it for a slow ride like no more than 1500-2000 revs. Keep an eye on the temp gage and check the coolant level frequently until the tank level stabilizes at no more than half full.


Install the tank cap and let the engine cool overnight. Check the fluid level in the morning, cold. If below half way down to the bottom add until it's half full. Do the cold check each next drive until the level stabilized at one-half full, cold.

Duke

[Frederick H.]

Re: '63 Removing Expansion Tank and Draining at Heater Hoses Before Draining Radiator

Yep - I remembered from way back about the test run after filling but forgot about the bouncing up and down to drop the coolant level. You mentioned Zerex G-05 coolant - I just bought a gallon of Prestone Max pre-mixed 56/44 and it states it is safe for aluminum applications. Is there a difference that is important to the overall cooling/metal interaction? I don't plan on driving more than a few miles before trying to get it judged at our regional in October and will attend to the remaining mechanicals and maintenance afterwards. Lots of things left to do and still won't be as complete as I would like but it will be the first judging so I will take all input constructively. I used to judge as well and I have it coming in as a Second Flight.
Thanks as always for your help.
Fred

[Frederick H.]

Re: '63 Removing Expansion Tank and Draining at Heater Hoses Before Draining Radiator

I just checked the differences in the two coolants - will see if I can return the Prestone and get the Zerex.

Thanks again.
Fred

[Leif A.]

Re: '63 Removing Expansion Tank and Draining at Heater Hoses Before Draining Radiator

I just checked the differences in the two coolants - will see if I can return the Prestone and get the Zerex.

Thanks again.
Fred

If the Prestone is unopened, there should be zero reasons the supplier won't take it back...especially, if you're buying the Zerex G05 from them.

[Duke W.]

Re: '63 Removing Expansion Tank and Draining at Heater Hoses Before Draining Radiator

I don't know the corrosion inhibitor chemistry of the Prestone you mentioned. Many modern cars use OAT type corrosion inhibitor packages like Dexcool, but Dexcool may be deficient in terms of solder protection because most modern cars have aluminum core radiators and heater cores with crimped on plastic side tanks... no solder.

The old "green" antifreeze was good at protecting ferrous and non-ferrous metals in the cooling system, but the inorganic salts over time precipitated out and clogged up radiator and heater core tubes.

Zerex G-05 was jointly developed and patented by Daimler-Benz and BASF and was OE in Mercedes Benz automobiles back in the eighties and into the nineties. It's patented corrosion inhibitor package is an HOAT (hybrid organic acid technology) type that provides excellent protection for all cooling system materials including solder. but without the heavy dose or inorganic salts like silicates the eventually plug up tubes. Until the patent expired, G-05 was only available from M-B dealers, and it was just called "Mercedes-Benz antifreeze".

It's the current "universal antifreeze" that protects all cooling system materials including solder, and I recommend it for ALL vintage cars with soldered cooling system components. Mix 50-60 percent with distilled water. Even most potable water may have undesirable minerals or added chemicals like chlorine, which is corrosive. At a buck or two a gallon distilled water is the best choice, and this blend is good for at least five years.

Duke

[Frederick H.]

Re: '63 Removing Expansion Tank and Draining at Heater Hoses Before Draining Radiator

Yep - always used distilled water - while the Prestone mentions it is safe for all metals, including aluminum, I don't recall seeing any mention of the solder thought - good info as always.

Thanks,
Fred

[John F.]

Re: '63 Removing Expansion Tank and Draining at Heater Hoses Before Draining Radiator

The battery could be removed without disconnecting the expansion tank.

[Don H.]

Re: '63 Removing Expansion Tank and Draining at Heater Hoses Before Draining Radiator

Above is absolutely true.. If the heater hoses are made long enough, as depicted in the AIM, the expansion tank can easily be pulled over and held by bungie cord to the oil filler pipe.
IMG_9636.jpg

[Mark E.]

Re: '63 Removing Expansion Tank and Draining at Heater Hoses Before Draining Radiator

Adding to Duke's method for flushing the system... it's common for the block drain plugs to be frozen. More harm than good can happen by forcing them. So the alternative is to backflush the block with the plugs intact.

[John F.]

Re: '63 Removing Expansion Tank and Draining at Heater Hoses Before Draining Radiator

Exactly the way I have been doing it on my cars.

[Frederick H.]

Re: '63 Removing Expansion Tank and Draining at Heater Hoses Before Draining Radiator

Yep - I would have used the bungie cord method but the hose clamps between the T-fitting and the tank were incorrect and needed to be changed for judging - plus when I saw how dirty the tank was on bottom, wanted to remove what I could.

Thanks All,
Fred