59BlueSilver

I was looking over my overflow hose routing and doesn’t look right to me. Just got this 65 with a Dewitt radiator and the overflow hose runs downward and out and not to the expansion tank. I can find diagrams of heater hose routing but not tank routing. Anyone have one?

LB66383

Got pictures? I'm guessing the engine is a small block, since I believe you're saying you have the tank inside the right fender. But do you have a small block radiator with no filler neck or a big block radiator with a filler neck? Where is the outlet tube on the filler neck on the tank connected, if anywhere?

leif.anderson93

If this is for your '65 and it's a small block, here are a couple of pictures from my '67...same routing for your '65. Note the hose runs BEHIND the hood support and is held in place there by one of the three tie straps that secure the hose to the inner fender well. Hope this helps.

59BlueSilver

No, it’s a BB but not original

65hihp

You have a very unusual configuration there on your modified 65. When you are using a BB copper or aluminum radiator with side reservoir tanks like you are, you normally will not also have a remote expansion tank. The overflow hose exiting under the radiator cap to the ground acts as the relief valve. You have that, but you also have an expansion tank with another overflow hose that runs from the drivers side reservoir tank all the way around through the top of the core support. Nothing about that set up is factory-like. But, if you like it that way, that is all that matters. I don't believe it is serving any purpose except perhaps to give you an extra quart or so of coolant in your system.

59BlueSilver

I thought it unusual when I looked at it closely, this was how I got the car. The reason I was is because I’m losing a little coolant every time I take it out and thought this setup might have something to do with it. Will it not be difficult to maintain a certain level in the tank?

0Tom@Dewitt

You have a radiator that we designed to eliminate the surge tank. The connection on the radiator is the pressure cap vent port. This should go directly to the ground. Since it is run to a pressurize tank, that makes that cap non-functional.

59BlueSilver

That does go directly to ground. Then what is the purpose of the fitting on the left side, and where should it go?

Nowhere Man

I would cap that off and eliminate the surge tank

59BlueSilver

I will do that, thanks, but still would like to know why that fitting is there.

Nowhere Man

it would appear someone was trying out smart someone else

0Tom@Dewitt

That port on the left side under the fitting is for the fan switch.

59BlueSilver

Thank you, Tom

0Tom@Dewitt

and now I see you have two hoses going to the ground so both caps are functional the way it is set up. You could leave it the way it is and make one cap 18# and the other 13# and the later would be the primary cap.

59BlueSilver

It seems dorky to me to have hoses running all over the place plus a non-functional tank, I like a clean engine bay. To get back to my original question, does this setup have anything to do with me having to add a cup of coolant after a drive?

LB66383

If it was me, I'd turn the expansion tank, or surge tank, or whatever you want to call it, into a coolant recovery tank like what is on the modern cars. Run the overflow from the radiator into the top of the tank, and modify the rest of the tank so it works as a coolant recovery/return. Making it a closed system. Then, if it continues to lose coolant, you'll know it's disappearing inside the engine somehow or out one of the radiator or heater hoses. Not through the radiator overflow.

59BlueSilver

Good idea, I’ll take a look at doing that, thanks!

59BlueSilver

I want to do that but need to understand exactly what needs to be done to the tank and the routing of hoses to have a recovery system. I’ve searched the internet and it gets confusing.