Coolant Overflow Question...

[mytvtmini]

Wife took her 1964 Sprite Mk III out yesterday (first time in 90 degree heat,stopped to eat, and when we came out we noticed coolant under the car. I checked hoses, radiator, etc. and it turns out the coolant came from the overflow hose. This is pre-expansion tank, our 1972 Midget I was driving has an expansion tank, so I'm wondering if this is normal?

We switched cars and I drove the Sprite home and it never got close to warm and didn't overflow when we got home. After the engine cooled I checked the coolant level and it was full. So I'm wondering if maybe it was a bit TOO full and the combination of that and a warm day caused the overflow???

Also, is there a way to add an expansion tank?

Thanks,

Mark

Waterford, VA
1964 Sprite Mk III
1972 Midget Mk III
1973 Corvette

 

[Trevor Jessie]

Welcome to the forum.

It sounds like a normal overflow, and you seem to have a grasp on the issue.

Those vertical flow tanks have a HUGE tank on top. I wouldn't think that an expansion tank would be necessary. If you are worried about accidentally overfilling it and making a mess on your drive you could just add a catch tank.

Hopefully someone will be able to tell you if it is possible to make a expansion tank without changing the neck of the radiator.

 

[mytvtmini]

Thanks for the information. Really appreciate it.

She wasn't running hot (according to the gauge), so I figured (hoped) it was normal overflow.

 

[jlaird]

Sure was normal. It was a bit overfull. Now that it has found its proper level you should have no more issue.

Wellcome to our place.

 

[Biff]

Mark,

I made an overflow retainer using a later spridget copper overflow tank on my vertical flow radiator. I replaced the standard radiator cap with a modified cap (I removed the spring and sealing ring and replaced them with a large rubber washer that would seal the neck) and then ran a small hose from the overflow radiator pipe to the copper catch tank. On the copper catch tank I installed a regular 7psi radiator cap. This way when the radiator burps it goes into the copper tank and when the engine/radiator cools it draws the burp back into the radiator just like on modern cars. Been running this rig now for 2 years without any problems. Another method I first used was to run the standard overflow line to my windshield washer bottle. When the radiator burped it went into the washer bottle and after things cooled down I could pour the washer bottle back into the radiator.

 

[mytvtmini]

Thanks for the responses. Definitely will make my wife more confident, since folks with more knowledge and experience than me say there's nothing to worry about.

I'll definitely set it up to run overflow into a "catch" bottle as a temporary solution. Then I'll try to set up the same system you have. Sounds like a winner.

Thanks again,

 

[sqbsprite]

Welcome Mark,
The overflow is normal if you overfill the radiator. I think it's interesting how the older cars would just spit out what they did not need like excess coolant, crankcase emissions, etc. We live in such an environmentally conscious world now, we forget the simpler times. I'm all for protecting the environment, but I hope they never expect the old cars to live up to today's standards. The biggest advantage to a closed coolant system is the cleaner your coolant will stay without exposure to air. A catch tank is a good idea especially if you have pets around that could be tempted by the sweet smell of coolant.

 

[cdsmith]

I made a catch tank out of an old Nalgene water bottle...

The cats live in the garage - didn't want any antifreeze on the ground - I don't want to kill the cats!

Works great.
cd

 

[Baz]

Someone here has a bottle of 'Old Speckled Hen' for a tank, stylish touch, can't remember who now...