Coolant Recovery tank

[ezernut9mm]

i didn't think a "recovery" bottle would do anything but catch overflow from one of our radiators. they work on crossflows, but not our style. am i right? at least mine won't "recover" any coolant that has overflowed into my bottle.
the previous owner tried to make it work by twisting a piece of wire around the brass piece on the underside of the radiator cap. this would allow coolant to enter the overflow bottle, but would not siphon it back up into the radiator. i removed the piece of wire and it doesn't overflow anymore.

[fmartin_gila1]

Chris,

When I put the overflow collector on my old dog, I just got the aftermarket setup from Autozoo. Mounted it up high as I could, and hooked it up to the brass tube under the cap. I use a 7 Lb. Lever-lock cap on mine. It would not suck back till I got the little tube resoldered into the neck, as it was just sucking air back in. I didn't know that it was not good till I put the overflow/recovery setup on. May be similar problem.

Fred

[LANCE65]

my '71 F250 Ranger has one...looks stock to me



-Lance

[71 LONG BED]

Hmm...something else to look for if I ever see a bump in the junkyard.

[cdherman]

Chris,

When I put the overflow collector on my old dog, I just got the aftermarket setup from Autozoo. Mounted it up high as I could, and hooked it up to the brass tube under the cap. I use a 7 Lb. Lever-lock cap on mine. It would not suck back till I got the little tube resoldered into the neck, as it was just sucking air back in. I didn't know that it was not good till I put the overflow/recovery setup on. May be similar problem.

Fred

This interests me in great detail. Just adding a bottle to the overflow tube does NOT create a coolant recovery system. There has to be a way to siphon the fluid back into the rad as it cools.

BUT, it seems to me that having the "little tube" resoldered into the neck under the cap would result in an unpressureized radiator. Meaning -- you can put a 7 or a 14 or whatever lb cap you want -- the rad will puke coolant into the overflow tank as it expands and it will not exceed atmosheric pressure (zero, relatively speaking).

Having a 7 or 11 lb cap on a radiator is useful --- water boils at a higher temp when its under a little pressure.

Looking at modern setups, it appears that they have the coolant outlet tube above the valve on the radiator cap. But they have another valve in the middle of the cap that allows the coolant to be pulled back into the radiator when a vacuum occurs.

Seems to me that you can get an existing, old style radiator to work with a coolant recovery system so long as you have the correct radiator cap AND the tube into the coolant recovery tank MUST always be under the level of the fluid in the recovery tank, so that it can siphon back.

So, I am guessing here. Who knows for sure?

[fmartin_gila1]

I don't know what the difference is supposed to be. The neck on my radiator is the original type, the cap is just a 7 lb leverlock type bought at NAPA. The aftermarket system was purchased at Autozone or Checker, and installed as high as possible beside the radiator. The overflow tube from the radiator goes directly to the overflow container connection which is at the bottom of it so it is always under the liquid level. As long as you keep any amount of liquid in the container, it has to suck fluid back into the radiator instead of air. Mine maintains the liquid level in the radiator totally full with no air pocket at all in the top of the radiator. The exclusion of any air eliminates the possibility of air circulating in the engine so there are no hot spots or steam pockets. Also, with the complete exclusion of air, rust does not seem to become a factor as fast as normally (in our older style cooling systems).

Fred

[Thunderfoot]

To setup a fluid recovery type over flow system all you have to do is get the correct type cap (newer style) and mount an overflow bottle that has the tube mounted at the bottom, or if it is from the top it has a tube that goes to the bottom of the reservoir.

There are “basically” two different radiator caps;

The ones are trucks came with didn’t have a good seal around the top of the cap (usually just paper type seal), only where it sealed around the “neck” of the radiator was important for a pressure seal, once fluid got past there it would just gravity feed out the overflow tube. The first “overflow” bottles that were added to cars were for the start of EPA safety to keep the antifreeze from just going on the ground… They just let fluid in from the top but no way for the fluid to get sucked back into the radiator, just air got sucked back in...

The “New” type of radiator caps have a good rubber type seal around the top of the cap so that both the areas between the “neck” and the “top” are sealed, this makes it so the Vacuum will work to suck the fluid back into the radiator when it/fluid cools; causing the fluid to flow back into the radiator from the external reservoir.

Radiator caps have a vacuum relief/siphon valve in them and there are a couple different types of valves, but basically both style caps have this, just that the older style, that isn’t sealed, will just suck air back into the system… Here is some good reading on them from Stant http://installer.aed-inc.com:8191/Stant ... dCap_4.htm.

I agree it is a good setup to use a fluid recovery system, as it keeps the air out of the cooling system and will make it work better and hinder the rust progression in the systems. Well worth the time to do.

Hope this helps fill in any blanks…

[ezernut9mm]

i'd like to say that i am learning here, but i am about as dense as they come so, what kind of cap do i need? i have an overflow bottle. the tube runs into the bottle and all the way to the bottom and sits under the fluid level in the bottle (it has a brass 90* fitting with a screen on it that also helps to weigh it down and keep it under the fluid level). do i need a "normally closed" type or "spring pressed" type of cap to get my overflow bottle to work as a recovery bottle? thanks for your patience.

[Thunderfoot]

i'd like to say that i am learning here, but i am about as dense as they come so, what kind of cap do i need? i have an overflow bottle. the tube runs into the bottle and all the way to the bottom and sits under the fluid level in the bottle (it has a brass 90* fitting with a screen on it that also helps to weigh it down and keep it under the fluid level). do i need a "normally closed" type or "spring pressed" type of cap to get my overflow bottle to work as a recovery bottle? thanks for your patience.

Yes....

Normally Closed - Spring Pressed....

They are the same. that is the cap is closing off the cooling system so to pressurize it "Normally Closed", it has a spring seat to hold the pressure hence the term "Spring Pressed"... same - same All caps are this way if they are set up for a recovery system or not, this is where it seals down inside the neck of the radiator (small part).

I’ll add some more info details of what to look for… the construction of the vacuum relief/siphon valve will not have an effect on the recovery function of the cap…

The thing you have to look at is if it has the seal on the top side of the cap, so that it will seal on the top of the radiator. This makes it so that it wont suck in air around the top, it will then be able to suck the fluid out of the tank.

Here is a picture of a cap that doesn't have the top seal. It won't work for a fluid recovery system...


This shows one with the top seal and how it relates to the radiator neck.


A couple things to note: If the top seal is cracked or the spring part above it is bad it will not work as it has to make a good seal on the top without leaks, so that it can suck the fluid back in when it cools off. Also, that there is no cracks or holes in the overflow hose or tube in the recovery tank.

You should be able to hook a vacuum tester up to the overflow hose and see if you can get a vacuum. You don’t have to get real carried away with a lot of vacuum as long as it has some you know it is sealed well enough for it to suck it out of the tank.

Hope this filled in more of the blanks, if not let me know and I’ll work it a different way.

[willowbilly3]

my '71 F250 Ranger has one...looks stock to me



-Lance

Lance, that is very interesting. It apparently was part of the auxiliary battery set up too. Was it a package deal? CS variation maybe?

[fmartin_gila1]

Apparently that is why mine works. The lever-lock cap must have the top seal in it. This radiator cap was there when I bought the old dog, and I bought the recovery tank and put it on, and it works. Never gave it any thought as to why.

Fred

[ezernut9mm]

d'oh!. the way the page opened on my comp had me thinking the spring pressed type and the normally closed type were the same. i didn't see the open or weighted type in the print so i was really confused. now i can see clearly. i have the right cap, it is just wore out. i'll get a new one. should i get a 7lb or 13lb cap?

i'd like to say that i am learning here, but i am about as dense as they come so, what kind of cap do i need? i have an overflow bottle. the tube runs into the bottle and all the way to the bottom and sits under the fluid level in the bottle (it has a brass 90* fitting with a screen on it that also helps to weigh it down and keep it under the fluid level). do i need a "normally closed" type or "spring pressed" type of cap to get my overflow bottle to work as a recovery bottle? thanks for your patience.

Yes....

Normally Closed - Spring Pressed....

They are the same. that is the cap is closing off the cooling system so to pressurize it "Normally Closed", it has a spring seat to hold the pressure hence the term "Spring Pressed"... same - same All caps are this way if they are set up for a recovery system or not, this is where it seals down inside the neck of the radiator (small part).

I’ll add some more info details of what to look for… the construction of the vacuum relief/siphon valve will not have an effect on the recovery function of the cap…

The thing you have to look at is if it has the seal on the top side of the cap, so that it will seal on the top of the radiator. This makes it so that it wont suck in air around the top, it will then be able to suck the fluid out of the tank.

Here is a picture of a cap that doesn't have the top seal. It won't work for a fluid recovery system...


This shows one with the top seal and how it relates to the radiator neck.


A couple things to note: If the top seal is cracked or the spring part above it is bad it will not work as it has to make a good seal on the top without leaks, so that it can suck the fluid back in when it cools off. Also, that there is no cracks or holes in the overflow hose or tube in the recovery tank.

You should be able to hook a vacuum tester up to the overflow hose and see if you can get a vacuum. You don’t have to get real carried away with a lot of vacuum as long as it has some you know it is sealed well enough for it to suck it out of the tank.

Hope this filled in more of the blanks, if not let me know and I’ll work it a different way.

[Thunderfoot]

d'oh!. the way the page opened on my comp had me thinking the spring pressed type and the normally closed type were the same. i didn't see the open or weighted type in the print so i was really confused. now i can see clearly. i have the right cap, it is just wore out. i'll get a new one. should i get a 7lb or 13lb cap?

I would get the 13lb for a street rig (and is what I have on my truck) as it raises the boiling point a little more. I only use 7lb or less on my racing engines at the track, where it isn't running long enough to get real hot anyways, and less pressure for any possible leaks internal or external...
Just what I have always done anyways.