Anti-Frezze expandtion thru overflow @ Shutdown

[hmsevans]

Anti-Frezze expandtion thru overflow @ Shutdown

I continue to lose about a Pint of antifreeze thru my overflow after a long run from my 1966 BJ8,It has happen 6 or 7 times
I have checked the level and its about 2" from the top of the filler.
Is it still too high or do I have other Problems?
What about an overflow tank,Are they a good idea on Healeys?

My Rad was flushed and cleaned 300 miles ago ,I do have the Heater valve turned off.I am running a Texas Cooler fan.
Thanks Mark

 

[Deleted member 8987]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Heat soak is pretty common. So common, all auto manufacturers went to a puke bottle as standard equipment.
You running stock pressure cap?
If too low a pressure, or if the cap is defective (especially if the "reach" into the fill neck isn't right) it will REALLY puke it out.
Another margue I work with has two different reach caps, and you gotta have the right one.

 

[Bob_Spidell]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Just let the radiator find its own level, then don't worry about it. I overfill a little, let the rad puke it out, then move on to whatever else needs fixing. An extra pint or so won't make much difference in cooling.

 

[John Turney]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

I have an aftermarket plasic overflow and it keeps the system full with no spill. The main thing you have to be aware of is the little tube off the side of the neck may not seal against the overflow tube well. I used some black silicone sealer to get a vacuum tight seal.

 

[Michael Oritt]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

A recovery tank (as opposed to an overflow tank) will keep coolant off the garage floor and your radiator topped off as well.

 

[Legal Bill]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Does anyone have a link to a good recovery tank that will fit somewhere under the hood of our cars?

 

[Randy Forbes]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Spridget/late model MGB recovery tank:

 

[gra]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

I used this SS tank as a recovery tank. Fits on left fender brace with a little adjustment here and there. https://cgi.ebay.com/ebaymotors/OVERFLOW-...=item4cf660ed1d

 

[Legal Bill]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Thanks gra. Does that thing have a pressure cap? It is hard to tell from the picture, but it just looks like a spin on cap.

 

[Legal Bill]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Spridget/late model MGB recovery tank:

Thanks Randy. I used to have a couple of those, but not any more. I always wondered how the coolant was supposed to return to the the radiator with those systems. I know the idea is that when the water cools it creates a vacuum in the radiator, but how does it pull the water through the radiator cap when the radiator is cool and the spring loaded seal is pushing against the inside of the radiator neck joint?

 

[TimK]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

I have the same question, Legal Bill!

 

[Bob_Spidell]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

I always wondered how the coolant was supposed to return to the the radiator with those systems. I know the idea is that when the water cools it creates a vacuum in the radiator, but how does it pull the water through the radiator cap when the radiator is cool and the spring loaded seal is pushing against the inside of the radiator neck joint?

In a recovery system, the radiator cap has a vacuum seal--a valve, basically--that seals up under pressure but opens under the vacuum produced when the coolant cools.

Nice writeup here:

https://homepages.donobi.net/sufuelpumps/...SYSTEMS_AND.pdf

 

[Legal Bill]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Ahh. So you have to use the right radiator cap.

 

[Legal Bill]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Or...now that I read it... maybe all the caps have the vacuum release valve.

 

[John Turney]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Yes, they all have the vaqcuum release valve. It keeps your radiator from collapsing when the coolant cools to room temperature.

The key to making these recovery systems work is having the cap and overflow hose vacuum tight to the outside. The typical radiator cap for a non-recovery system has a primary seal but not a secondary seal. Instead of a rubber secondary seal there is a metal "splash guard" that keeps coolant between the primary seal and the top of the radiator neck from splashing out before it goes on it's way out the overflow hose. Caps made for recovery duty have a rubber secondary seal. It's possible to cut one out of sheet rubber and put it on top of (when the cap is upside down) the metal "splash guard".

Also, on mine, the little overflow tube off the side of the neck isn't a nice round tube, but a folded piece of brass that makes kind of a tube, but has a big seam along it's length. The overflow hose doesn't tightly seal against it without some silicone and a really tight clamp.

 

[RAC68]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Hi All,

For those interested, a while back I wrote a summary of cooling alternatives installed on my Healey. A copy is posted on John Sims site Healey6 at

https://www.healey6.com/Technical/I%20always%20wanted%20a%20COOL%20Car.pdf

One of the things present is a non-pressurized very inexpensive coolant recovery system that has served extremely well and took all but 15 minutes to create and install. Since all my modifications are completely reversible and hopefully appear to belong, this also can be quickly eliminated for concourse participations.

All the best,
Ray (64BJ8P1)

 

[Legal Bill]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Ray, how is that gear oil bottle secured?

 

[Legal Bill]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Oh, and who sells those original style thermostats?

 

[RAC68]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Hi Bill,

The container can be anything that will handle the heat without melting and fit within the space available. It should be mounted close enough for the vacuum to retrieve the coolant. My container fits nicely within the area and I have installed a small platform to the baffle (baffle also described) to rest the it upon. The overflow tube from the radiator neck, supported by the top radiator tube hook, provides sufficient support to keep the upper portion of the container in place. Depending upon your container, you can install a retaining band onto the radiator mounting bolt (similar to the upper portion of the windshield washer bottle holder) to further secured the container.

The original style thermostats are sold by Moss, British Car Specialists, and a number of other organizations. I know if you Google the web you will find a number of sources, however, they all consider them special.

Let me know if you would like and I will take and post a picture of the mounting.

All the best,
Ray (64BJ8P1)

 

[gra]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

I used the tank I linked above, some vacuum hose the same size as overflow hose and a NAPA Balkamp 703-1411 radiator cap to rig the recovery system. My recollection is that the radiator cap was less than 10 bucks.

As others stated just about any container you like will work if you have the right cap and hose connections. Here is a link to an earlier thread that may help. https://www.britishcarforum.com/bcforum/ubbthreads.php/topics/749858/Re_Radiator_overflow_tank

Good luck!