Overflow Tank question

[patrickt]

Originally Posted by Excaliber

So the last time this was an issue was nine years ago? From that I would speculate that about every 10 years, or less, someone manages to find the one cap that is not a recovery type.

No, that was the last time someone realized that it was an issue, and then a discussion ensued. I think I've posted on it since then, frankly. Honestly, I find it easier to just open the surge tank, eyeball the coolant condition, maybe even use one of these handy dandy little test strips I have sitting around here, and then top off as necessary.

[Archrms]

Tim, thanks for the link on the recovery conversion. I am amazed that it is such a simple procedure, and costs virtually nothing.

I also did not know there were recovery vs non-recovery radiator caps, but it is something I will look for now. Thanks Patrick.

[Jim Norris]

After reading this thread I went out to check my own setup. On mine, the small hose from the expansion tank (shiny tank) runs directly to the bottom of the overflow tank (the petcock is in the open position) and another small hose is attached to the upper overflow tank fitting and run down the side of the tank. This hose is open to the ground.
Does this setup possibly act as a recovery system allowing accumulated coolant resting at bottom of the tank to be drawn back up the hose and into the expansion tank, assuming I have a recovery type cap?

[Excaliber]

That is the BEST setup Jim, and it will work perfectly. Some overflow tanks, like mine, simply vent or purge any excess from the tank out of the top through a vented cap. That overflow would then run all over the sides of the holding tank and spill out all around the engine compartment area and ground. I would much prefer a tank with a second hose from it's cap that directs any overflow straight to the ground.

It's important to NOT fill up your overflow tank when the system is cold because you need to leave room for expansion and additional filling of the overflow when the engine is hot.

Some folks say you should leave a little room, leave the water a little low, in the surge tank mounted on the motor. That way some expansion can occur within the engine without pushing the water out to the overflow tank.

[Archrms]

Jim,

It sound like you have the same setup I have for the overflow tank. I did the modifications as per Tim's link this past weekend. However, the setup you described by reversing the input hose to the bottom of the tank and making the top hose an overflow seems a better idea - and cleaner. Just make sure the vent hole at the top of the tank is plugged.

Also, I checked the cap on my expansion tank, and is was NOT a recovery type cap. I need to replace that next.

[patrickt]

Here you go, Ernie. This is a shot of the underside of my radiator cap that failed the Putnam Suck Test.

[bkozlow]

As your OVER FLOW TANK look at a 1968 Mustang washer fluid tank about $40, hopefully the picture made it. I have used this tank on ever car since 1969, they look great and attach to any flat surface, can be drilled and tapped on the bottom for the radiator neck over flow and drilled at the top for an over flow to the ground. In the picture, you can see the amount of fluid easily.

Bill K

[patrickt]

Below is a note that the OP sent me along with two pics that he could not get to post.

Finally I can easily attach the pictures. See one of them is the white transparent canister, I never had any coolant in there, whether engine is hot or cold. The other picture is the right hand side of the radiator. The small leak is from the bottom of the radiator. I check the cap and little black side cap on the radiator and they feel dry. And no leak when the car is not running and cold. I don’t have two tanks like many folks mention in the posts. Just one white empty canister.

I also drove in the neighborhood for a bit and temp raises to 180 and stays there, no overheating. Important to mention, this is small block 400 chevy engine, I know people blame for that… but it was factored in the price.

[patrickt]

What I would do is fill the radiator up to the top when cold and then fill that white canister up about three inches from the bottom when cold. Draw a line on the canister where you filled it up to. Then drive it around and get it good and hot and see if the level goes up or not. If it goes up when hot, wait for it to get cold and see if the level goes back down to the line.

[Eyvazk]

Thanks Patrick, I will try it over the weekend. Getting to the radiator seems like will be a bit challenge given the location of it deep in the nose.