'72 C20 rad overflow recovery tank

[oldasi]

Just started to put this vehicle ('72 C20 Long Horn) on the road and noticed rad overflow, we are having a heat wave here right now.
Anyone know if there was a recovery tank available, and is it worth installing. Looks messy seeing it out flow onto the ground

[In The Ten Ring]

That's how they used to come man, overflowed right onto the ground and then you refilled the radiator as needed. I guess it kept the stray dog population down as a bonus. LOL

The Parts Forum has a member that sells a modern copy of the OEM optional overflow tank fairly often and various companies sell a version.

Summit
Jegs
LMC....just about any vendor carries a version or several.

Use the search feature, there are threads on the site about this.

Here is a good thread on it, lots of pics for ideas. I have this task coming up by next March.

http://67-72chevytrucks.com/vboard/s...d.php?t=476075

[Stocker]

Coolant recovery tank is a great thing IMHO. Be sure to use a radiator cap made for a closed (or sealed) system. Without that, coolant will not be sucked back into the radiator when the system cools down.

[oldasi]

I have just replaced the rad cap as the seal didn't look that good and following that when parked it leaked out the overflow. Now on the same day we've had the temperature skyrocket so don't know if that caused the overflow or the new cap.
So the rad cap should hold pressure yet the overflow tank doesn't need to have a sealed cap as it would need to allow air into the recovery tank, least that's my thinking

[Stocker]

Originally Posted by oldasi

So the rad cap should hold pressure yet the overflow tank doesn't need to have a sealed cap as it would need to allow air into the recovery tank, least that's my thinking

Your thinking is correct!

[FirstOwner69]

If you are filling the radiator to the top... don't. The level in original systems is supposed to 2 or 3 inches below the neck where the cap seals. Set it there then let it seek its own level.

[Stocker]

Originally Posted by FirstOwner69

If you are filling the radiator to the top... don't. The level in original systems is supposed to 2 or 3 inches below the neck where the cap seals. Set it there then let it seek its own level.

That is certainly true, assuming no recovery tank.... which is one reason I like having that recovery tank. You can fill it to the top.

[FirstOwner69]

Originally Posted by Stocker

That is certainly true, assuming no recovery tank.... which is one reason I like having that recovery tank. You can fill it to the top.

My original 4 row radiator has a mark that is labeled "fill level" or some such thing. That's the cold level. I don't think my truck ever puked coolant in the 48 years I've owned it. The truck never overheated/overflowed even with a 2500# cab over camper, boat in tow and A/C on.
That doesn't mean its a bad idea to have a tank though. I'm curious how much more coolant is in the radiator when it's filled to the top with a tank in use.

[HO455]

Do a search of the forum as there are several threads on this. One of the cleanest seems to be using a 80's g-body tank. I used a first gen S10 tank on my Burban but it did require some bracket fabrication. (Photos in WMB link below) Or some folks use a factory windshield washer tank and bracket.

[tdangle]

I bought a generic kit from Autozone and replaced the cap. Works great.

[71CHEVYSHORTBED402]

Like HO455 said, lots of information on this. I can't speak for trucks with an Aux. battery, but I think they were recovery tanks placed on top of the RH inner fender.

Without an aux. battery, these expansion tanks were factory installed, though rare. They were also dealer installed. Seems they started adding tanks around 1971ish (i.e., California requirements), and they were mandatory in all states in 1973.